KR102173143B1 - Current detecting device - Google Patents

Abstract

The present invention relates to a current detection device with a new structure, which can secure high linearity compared to a conventional current transformer (CT), can have less influence by noise compared to Rogowski coils, can reduce the weight, the thickness and the length, and can greatly reduce manufacturing costs. The current detection device comprises: a substrate having a through hole through which a main line passes; an axial lead inductor which is disposed along the periphery of the through hole, and disposed so that an angle between adjacent other axial lead inductors forms a right angle; and a connection pattern portion printed on the substrate to interconnect the axial lead inductor or to form a current lead-in and lead-out path. At least one connection pattern portion of the connection pattern portions includes an interphase interference canceling pattern portion passing through the substrate of the current detection device of another phase adjacent to the substrate in a zigzag form. According to the present invention, the axial lead inductor disposed around the through hole is disposed so as to form a right angle with respect to adjacent other axial lead inductors, thereby detecting current with a minimum number of axial lead inductors while linearity is increased, designing the device to have a compact volume, and greatly reducing product costs by using a standardized product. At least one of the connection pattern portions interconnecting the axial lead inductors is formed as the interphase interference canceling pattern portion which cancels interphase interference with respect to the current detection device of the adjacent phase, so that a three-phase current detection device which can suppress noise and the interphase interference caused by peripheral lines and can detect three-phase current can be manufactured in a very compact size.

Description

Current detection device {CURRENT DETECTING DEVICE}

The present invention relates to a current detection device, and more particularly, it is possible to secure high linearity compared to a conventional CT (Current Transformer), less influence by noise compared to a Rogowski coil, and easy to manufacture, light, thin and short. It relates to a current detection device of a new structure that can greatly reduce the unit cost.

In general, an overcurrent protection relay for protecting the motor is installed at the power stage of a three-phase motor. The overcurrent protection relay is equipped with a current detection device for detecting a current flowing through the motor, and performs a trip operation according to the current detected by the current detection device.

1 is a perspective view showing an example of a general overcurrent protection relay. Referring to FIG. 1, a user operation unit 110 is provided on an upper surface of the relay body 100, and an output terminal 120 for power and contact is provided on the front surface. A current detection device 150 is installed under the relay body 100, and the three-phase power lines 140 pass through each of the through holes 130 formed in the current detection device 150.

Referring to the block diagram of FIG. 2, the current detection device 150 detects the current flowing to the motor from the power line 140 passing through the through hole 130, and the current information calculator 112 in the relay body 100 ) Calculates the current value from the detection signal. The operation time calculator 114 calculates an operation time by comparing the value set by the user operation unit 110 with the calculated current value, and the contact relay 118 of the overcurrent protection relay is driven by the contact driver 116 Perform a protective action.

A general current detection device may suffice to ensure a linearity of about 110%, but the current detection device 150 installed in the motor protection relay must detect overcurrent by 300% or more (more preferably 1,000% or more). It is necessary to ensure high linearity.

The conventional current detection device 150 used a CT (Current Transformer), a Rogowski coil, a Hall-Effect Sensor, or the like, which is commonly referred to as an instrument current transformer.

The CT outputs a current proportional to the primary current (the mains current passing through the through hole) by winding a winding around a magnetic core. As the number of windings increases, the current can be converted at a higher magnification, and accordingly, a large number of windings is required to secure a wide range of linearity. In addition, since the magnetic core is used, it is necessary to increase the cross-sectional area of the core to prevent magnetic saturation in a wide current region. For this reason, when using a CT for overcurrent detection, there is a problem that the volume and cost increase. The Hall sensor also has a problem of increasing the volume and unit cost like a CT by using a magnetic core, and it is not used well because it is very expensive.

The Rogowski coil uses an air core, not a magnetic material, and theoretically has no magnetic saturation and has the advantage of securing a wide range of linearity. However, there is a disadvantage in that the degree of coupling between the primary side and the secondary side is low, and thus the effect of noise is large. Also, since the Rogowski coil has a lower output characteristic than a CT, it is necessary to use an integrator with a high amplification ratio to detect the current, and there is a problem that noise is amplified together during the amplification process. Further, in order to minimize the effect of noise, a noise shielding plate is required, which acts as a factor that increases the manufacturing cost and volume even though the magnetic core is not used.

Meanwhile, Korean Patent Registration No. 10-2013286 proposes a current sensing device for arranging a plurality of rod-shaped sliced coils in a polygonal shape on a substrate and electrically connecting two adjacent sliced coils. According to the prior literature, it has the effect of reducing the amount of leakage magnetic flux of the current sensing device, improving the accuracy of the measured current, and reducing the manufacturing cost and volume.

However, the prior literature above is arranged so that the inner angle formed by the two adjacent intercept coils exceeds 90 degrees in order to prevent the signal distortion phenomenon in which the level of the current waveform changes (see paragraph [0074-0075]), 6 or more and 20 or less section coils are arranged around the perimeter, which acts as a factor to increase the volume of the current sensing device. In addition, there is a problem in that the price is greatly increased and the volume of the device is increased by installing a leakage magnetic field detector such as a Hall sensor between the sliced coils.

Korean Patent Registration No. 10-2013286

The present invention can significantly reduce the volume by arranging a minimum expedition lead inductor around the through hole through which the main line passes, and at least one of the connection pattern portions for interconnecting the expedition lead inductor is inter-phase with respect to the current detection device of the neighboring phase. By forming an interphase interference canceling pattern part that cancels the interference phenomenon, noise and interphase interference phenomena caused by surrounding lines can be suppressed, a three-phase current detection device can be manufactured in a very compact size, and manufacturing cost can be greatly reduced. It is an object of the present invention to provide a current detection device.

Further, according to the present invention, at least one of the connection pattern portions for interconnecting the expeditionary lead inductor is formed to include a noise shielding pattern portion forming a magnetic flux component orthogonal to the magnetic flux direction of the main line, By blocking, it is possible to secure high linearity compared to CT, while being robust to noise, to improve coupling, and to greatly reduce manufacturing cost.

In addition, another object of the present invention is to significantly reduce the size of a current detection device by configuring a phase current detection pattern and an image current detection pattern on the upper and lower surfaces of a multilayer substrate, respectively.

A current detection device according to an embodiment of the present invention includes: a substrate having a through hole through which a main line passes; An expedition lead inductor disposed along the periphery of the through hole and disposed so that an angle between the axes of the adjacent axial lead inductors forms a right angle; And a connection pattern part printed on the substrate to interconnect the expedition lead inductor or form a current drawing or drawing path, wherein at least one connection pattern part of the connection pattern part is a current detection device of another phase adjacent to the substrate. It includes an interphase interference canceling pattern portion passing through the substrate in a zigzag form.

In the current detection device according to another embodiment of the present invention, the expedition lead inductor has a lead drawn out of a tube body, a magnetic core is disposed in the tube body along an axial direction, and a coil is wound around the magnetic core. , On one side of the tube, a colored band indicating the direction of the current and the inductance value is printed.

In the current detection apparatus according to another embodiment of the present invention, at least one of the connection pattern portions is printed to have a pattern passing through a path forming a concentric circle with the through hole along the periphery of the through hole. It includes a noise shielding pattern portion for forming a magnetic flux component orthogonal to the magnetic flux direction of the main line.

delete

In the current detection device according to another embodiment of the present invention, the interphase interference canceling pattern part includes a via hole vertically penetrating the substrate and the substrate of the current detection device of the neighboring phase, and at an end of the expedition lead inductor. The upper and lower portions are alternately formed between a vertical connection pattern portion extending in a vertical direction and electrically connected to the via hole, and the via hole formed in the substrate and the via hole formed in the substrate of the current detection device of the neighboring phase. It includes a zigzag connection pattern portion that is cross-connected to each other.

In the current detection device according to another embodiment of the present invention, the zigzag connection pattern portion is disposed to cross the zigzag connection pattern portion formed in the current detection device of the other adjacent phase and spaced vertically apart.

A current detection device according to another embodiment of the present invention includes a phase a substrate for detecting a current of a phase among three phase currents, a b-phase substrate for detecting a current of the b phase, and a c-phase for detecting a current of the c phase. Substrates are arranged adjacent to each other in sequence, and the through-hole, the expedition lead inductor, the connection pattern part, and the phase-to-phase interference cancellation are provided on top surfaces of each of the phase a substrate, the phase b substrate, and the phase c substrate. A phase current detection device including a pattern part is individually installed to be insulated from each other, and is disposed along the periphery of the through hole on the rear surfaces of the a-phase substrate, the b-phase substrate, and the c-phase substrate to detect other neighboring image currents An expeditionary lead inductor for video current detection, which is disposed so that an angle between axes with the expeditionary lead inductor is at right angles, and the expeditionary lead inductor for video current detection are placed on the a-phase substrate, the b-phase substrate, and the c-phase substrate. An image current detection device including a connection pattern portion for detecting image current that is connected to each other is installed.

According to the current detection device of the present invention, the far lead inductor disposed around the through hole is disposed so as to form a right angle with respect to another neighboring far lead inductor, thereby improving linearity and detecting the current with a minimum of the far lead inductor. The volume can be designed to be compact, and product cost can be greatly reduced by using standardized products, and at least one of the connection pattern parts interconnecting the expeditionary lead inductor cancels the phase-to-phase interference with respect to the neighboring phase current detection device. By forming the inter-phase interference canceling pattern portion, it is possible to suppress noise and inter-phase interference phenomena caused by peripheral lines, and there is an effect that a three-phase current detection device for detecting a three-phase current can be manufactured in a very compact size.

In addition, according to the present invention, at least one of the connection pattern portions interconnecting the expedient lead inductor includes a noise shielding pattern portion forming a magnetic flux component orthogonal to the magnetic flux direction of the main line, thereby being robust against noise and improving the phase coupling degree. It works.

Further, according to the present invention, there is an effect that the size of the current detection device can be drastically reduced by configuring the phase current detection pattern and the image current detection pattern on the upper and lower surfaces of the multilayer substrate, respectively.

1 is a perspective view showing an example of a general overcurrent protection relay,
2 is a block diagram showing an example of a general overcurrent protection relay;
3 is a plan view illustrating the basic structure of a current detection device according to the present invention;
4 is a plan view showing an embodiment of a current detection device according to the present invention;
5 is a perspective view illustrating an interphase interference cancellation pattern unit in the present invention,
6 is a conceptual diagram illustrating a process of eliminating an interference phenomenon between phase currents by an interphase interference cancellation pattern unit in the present invention;
7 is a plan view showing another embodiment of a current detection device according to the present invention;
8 is a plan view showing an embodiment of image current detection by the current detection device according to the present invention;
9 is a plan view showing another embodiment of the image current detection of the current detection device according to the present invention, and
10 is a plan view showing an example in which a phase current detection configuration and an image current detection configuration are printed on a multilayer substrate in the current detection device according to the present invention.

Hereinafter, specific embodiments according to the present invention will be described with reference to the accompanying drawings. However, this is not intended to limit the present invention to a specific embodiment, it is to be understood as including all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

Throughout the specification, portions having similar configurations and operations are denoted by the same reference numerals. In addition, the drawings attached to the present invention are for convenience of explanation, and the shape and relative scale may be exaggerated or omitted.

In describing the embodiments in detail, overlapping descriptions or descriptions of technologies that are obvious in the art have been omitted. In addition, in the following description, when a certain part "includes" other components, it means that components may be further included in addition to the described components unless otherwise stated.

In addition, terms such as "~ unit", "~ group", and "~ module" described in the specification mean a unit that processes at least one function or operation, which can be implemented by hardware or software or a combination of hardware and software. I can. In addition, when a part is electrically connected to another part, this includes not only a case in which it is directly connected but also a case in which it is connected with a different configuration in the middle.

Terms including ordinal numbers, such as first and second, may be used to describe various elements, but the elements are not limited by the terms. These terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a second component may be referred to as a first component, and similarly, a first component may be referred to as a second component.

3 is a plan view illustrating a basic structure of a current detection device according to the present invention. Referring to FIG. 3, the current detection device of the present invention is a device that detects a current of a main line (not shown) passing through the through hole 210 formed on the substrate 220, and is a conventional CT (Current Transformer) or Unlike the Rogowski coil, it is a current detection device using an axial lead inductor (230).

Here, the expedition lead inductor 230 has a structure in which a lead is drawn out of the tube body, a magnetic core is provided in the tube body along the axial direction, and a coil is wound around the magnetic core (see FIG. 6 ). As is commonly known, an expedition lead inductor is an element mainly used for a noise filter of a power supply terminal, and like a commercial resistance element, a colored band is printed on the outside to indicate the direction of the current and the inductance value. The present invention provides an advantage of greatly improving assembly performance by using a standardized low-cost expedition lead inductor, which greatly reduces the manufacturing cost, and allows the expedition lead inductor to be arranged along the current flow direction by identifying a colored band. do.

As shown, the far lead inductor 230 is disposed so that an angle between the axes of the other adjacent lead inductors 230 is at right angles. The expedition lead inductor 230 may be installed by soldering an end lead to the substrate 220. In addition, the connection pattern portion 240 is printed on the substrate 220. The connection pattern part 240 interconnects the expedient lead inductors 230 or forms a current drawing or drawing path at an end of the expedient lead inductor 230. In the present invention, since the far lead inductors 230 form an inner angle of 90 degrees, the phase current can be detected with only four far lead inductors 230. In addition, by using only the four expeditionary lead inductors 230, a current detection device can be provided in a very compact volume.

At this time, a countermeasure is required to solve the noise problem caused by configuring the current detection device with the expedition lead inductor 230. The present invention provides noise countermeasures for main lines and noise countermeasures for peripheral lines (lines of other adjacent phases) with a simple circuit pattern formed on the substrate 220. Referring to Fig. 4 below, noise countermeasures in the present invention will be described.

Figure 4 is a plan view showing an embodiment of the current detection device according to the present invention, Figure 5 is a perspective view illustrating an interphase interference cancellation pattern unit in the present invention, Figure 6 is a phase current by the phase interference cancellation pattern unit in the present invention It is a conceptual diagram illustrating a process of solving the interference phenomenon between the liver, and Figure 7 is a plan view showing another embodiment of the current detection device according to the present invention.

Referring to FIG. 4, an a-phase substrate 220a, a b-phase substrate 220b, and a c-phase substrate 220c are arranged side by side. Phases a, b, and c may be referred to as phases such as R, S, T, or u, v, w, etc., as commonly known, and are symbols for distinguishing different phases. In addition, although it has been exemplified that the three-phase substrates are configured separately, respectively, in order to help the understanding of the present invention, the three-phase current detection device may be formed on the same substrate. That is, in the present invention, a phase, b phase, and c phase may be understood as a concept for classifying a current phase, not a concept of physical classification.

Referring to FIG. 4, at least one of the connection pattern parts 240 includes a pattern passing through a path forming a concentric circle with the through hole along the circumference of the through holes 210a, 210b, and 210c. It includes a noise shielding pattern portion 250 that is printed to have. In the illustrated example, in all three-phase substrates, the noise shielding pattern portion 250 extending from the current drawing portion is identically shielded around the through holes 210a, 201b, and 210c. Of course, the noise shielding pattern part 250 may extend from another connection pattern part 240.

The a-phase main line passing through the a-phase through hole 210a penetrates in a direction orthogonal to the a-phase substrate 220a. The noise shielding pattern part 250 on the a-phase forms a closed loop orthogonal to the main preference. Therefore, it has a magnetic flux component that is orthogonal to the magnetic flux direction of the main line, and noise generated by the main line can be shielded. This shielding applies equally to phase b and phase c. In the present invention, by forming a pattern such that the noise shielding pattern portion 250 is included in one of the connection pattern portions 240, it is possible to very easily shield the noise of the main line.

Referring to FIG. 4, at least one connection pattern part 240 of the connection pattern part 240 includes an inter-phase interference canceling pattern part 300 passing through a substrate of another adjacent phase in a zigzag form. FIG. 5 is a diagram illustrating the interphase interference cancellation pattern unit 300 in three dimensions, and the interphase interference cancellation pattern unit 300 will be described in detail with reference to FIG. 5.

FIG. 5 is a diagram in which the phase a-phase interference canceling pattern portions 260a, 310, and 320 and the phase-b phase interference canceling pattern portions 260b, 330, and 340 are formed over the a-phase substrate 220a and the b-phase substrate 220b. An example is shown.

Referring to FIG. 5, the phase-a-phase interference canceling pattern portion includes a-phase via hole 320 penetrating the a-phase substrate 220a and the b-phase substrate 220b in a vertical direction, and a-phase expedition lead inductor 230. The a-phase vertical connection pattern portion 260a extending in the vertical direction from the end and electrically connected to the a-phase via hole 320 and the phase a via hole 320 are interconnected by alternately crossing the upper and lower portions It is composed of a-phase zigzag connection pattern portion 310.

Likewise, the b-phase interference canceling pattern portion is perpendicular to the b-phase via hole 340 penetrating the b-phase substrate 220b and the a-phase substrate 220a in a vertical direction, and the b-phase expedition lead inductor 230 The b-phase vertical connection pattern portion 260b extending in the direction and electrically connected to the b-phase via hole 340, and the b-phase interconnected by alternately crossing the upper and lower portions between the b-phase via holes 340 It is composed of a zigzag connection pattern portion 330.

As shown, the a-phase zigzag connection pattern portion 310 and the b-phase zigzag connection pattern portion 330 are arranged to be spaced apart vertically to cross each other. Therefore, it is possible to maintain the state of insulation between phases.

Referring to FIG. 6, an inter-phase interference canceling pattern part 300 is formed at a position adjacent to the a-phase current detection device and the b-phase current detection device. The position where the interphase interference canceling pattern part 300 is formed is a point where the magnetic flux Ba due to the current ia of a phase and the magnetic flux Bb due to the current ib of b phase intersect, as indicated by arrows in the drawing. The interphase interference cancellation pattern unit 300 is affected by both the magnetic flux Ba and the magnetic flux Bb. As shown, in the interphase interference cancellation pattern unit 300, two magnetic fluxes flow in opposite directions.

At this time, since the phase a-phase interference cancellation pattern part is formed in a zigzag manner via the b-phase substrate 220b, an electromotive force proportional to the magnetic flux difference (Ba-Bb) of the two phases is output (Bb in the case of the phase-b interference cancellation pattern part) -Output the electromotive force proportional to Ba). That is, since the magnetic flux component generated in the b-phase is canceled and subtracted, inter-phase interference can be minimized. Such an inter-phase interference cancellation effect can be expected in the same manner in the inter-phase interference cancellation pattern unit 300 between the b-phase and c-phase.

The present invention is not required to install an additional noise shielding configuration, by configuring some of the patterns of the connection pattern portion 240 to include the noise shielding pattern portion 250 and the phase interference canceling pattern portion 300, that is, , Only by specializing the pattern formed on the substrate 220, noise shielding for the main line and interference suppression for the surrounding lines can be achieved. This reduces the current detection device to the minimum possible and acts as a factor that can greatly reduce the manufacturing cost. Ultimately, it is possible to provide a current detection device that has improved linearity, good coupling, and robust against noise by replacing the conventional CT or Rogowski coil.

Meanwhile, in the embodiment of FIG. 4, it has been described that current detection devices of three phases a, b, and c are arranged in a row, but the present invention may have the same arrangement as in FIG. 7. The arrangement of FIG. 7 shows an arrangement example in which the vertical width of the three-phase current detection device increases but the left and right widths decrease. In the example of FIG. 7, the entire left and right width of the three-phase current detection device is reduced, but the distance between the phases in the border area adjacent to each phase is the same as the example of FIG. 4. The current detection device of the present invention may be changed to an arrangement as shown in FIG. 7 or another arrangement not illustrated depending on the object to be applied.

8 is a plan view showing an embodiment of image current detection by the current detection device according to the present invention, FIG. 9 is a plan view showing another embodiment of image current detection by the current detection device according to the present invention, and FIG. A plan view showing an example in which a phase current detection configuration and an image current detection configuration are printed on a multilayer substrate in the current detection device according to the present invention.

Referring to FIG. 8, the current detection apparatus of the present invention can be applied to image current detection as well as phase current detection. In order to detect the image current, the a-phase, b-phase, and c-phase video current detection expedition lead inductor 280 are all connected in series, and the angle between the axes is perpendicular to the other neighboring video current detection expedition lead inductor 280. . Among the video current detection connection pattern portions 290 connecting the video current detection expeditionary lead inductors 280, the b-phase video current detection connection pattern part 290 forms a current inlet and a current draw. The image current detection apparatus may have an arrangement as shown in FIG. 9 or may be designed in a different arrangement.

Here, the advantage of detecting the image current using the expeditionary lead inductor 280 for image current detection is that the phase current detection device and the image current detection device can be configured together using a double-sided substrate, as illustrated in FIG. 10. Point. As depicted by a solid line in FIG. 10, a three-phase current detection device may be configured, and a video current detection device may be configured as illustrated by a dotted line on the rear surface of the substrate. Such a substrate configuration enables the size of the current detection device to be drastically reduced.

The invention disclosed above can be variously modified within a range that does not damage the basic idea. That is, all of the above embodiments should be interpreted as illustratively and not limitedly. Therefore, the scope of protection of the present invention should be determined according to the appended claims rather than the above-described embodiments, and if the components defined in the appended claims are substituted with equivalents, it should be considered as belonging to the protection scope of the present invention.

210: through hole 210a: a-phase through hole
210b: b-phase through hole 210c: c-phase through hole
220: substrate 220a: a-phase substrate
220b: b-phase substrate 220c: c-phase substrate
230: expedition lead inductor 240: connection pattern portion
250: noise shielding pattern portion 260a: a phase vertical connection pattern portion
260b: b-phase vertical connection pattern portion
280: Expedition lead inductor for detecting image current
290: video current detection connection pattern part
300: Inter-phase interference cancellation pattern portion 310: A-phase zigzag connection pattern portion
320: a-phase via hole 330: b-phase zigzag connection pattern portion
340: b-phase via hole

Claims (7)

A substrate having a through hole through which the main line passes;
An expedition lead inductor disposed along the periphery of the through hole and disposed so that an angle between the axes of the adjacent axial lead inductors forms a right angle; And
A connection pattern part printed on the substrate to interconnect the expedition lead inductor or to form a current drawing or drawing path
Including,
At least one connection pattern part of the connection pattern part includes an interphase interference cancellation pattern part passing through a substrate of a current detection device of another phase adjacent to the substrate in a zigzag form.
The method of claim 1,
In the expeditionary lead inductor, a lead is drawn out of the tube body, a magnetic core is disposed in the tube body along an axial direction, a coil is wound around the magnetic core, and a current direction and inductance value are measured at one side of the tube body. The current detection device in which the indicated colored band is printed.
The method of claim 1,
At least one of the connection pattern portions is printed to have a pattern passing through a path forming a concentric circle with the through hole along the circumference of the through hole to form a magnetic flux component orthogonal to the magnetic flux direction of the main line. Current detection device including a shielding pattern portion.
delete The method of claim 1,
The interphase interference canceling pattern part includes a via hole vertically penetrating the substrate and the substrate of the current detection device of the neighboring phase, and a vertical extending from the end of the expedition lead inductor in a vertical direction and electrically connected to the via hole. A current detection device comprising a connection pattern part and a zigzag connection pattern part which is connected to each other by alternately crossing upper and lower parts between the via hole formed in the substrate and the via hole formed in the substrate of the neighboring other phase current detection device .
The method of claim 5,
The zigzag connection pattern portion is disposed so as to cross the zigzag connection pattern portion formed in the current detection device of the other adjacent phase and spaced apart vertically to cross each other.
The method according to any one of claims 1, 5, and 6,
In the substrate, an a-phase substrate for detecting a current of the a-phase among the three-phase currents, a b-phase substrate for detecting a current of the b-phase, and a c-phase substrate for detecting a current of the c-phase are sequentially disposed adjacent to each other,
A phase current detection device including the through hole, the expedition lead inductor, the connection pattern part, and the interphase interference canceling pattern part are provided on top surfaces of each of the a-phase substrate, the b-phase substrate, and the c-phase substrate. Installed individually to be insulated,
The a-phase substrate, the b-phase substrate, and the c-phase substrate are disposed along the circumference of the through-hole on the rear surfaces of each of the phase-a-phase substrates, but are arranged so that the angle between the axes with the expeditionary lead inductor for detecting another neighboring image current forms a right angle A video current detection device comprising a detection expedition lead inductor and a video current detection connection pattern unit interconnecting the a-phase substrate, the b-phase substrate, and the c-phase substrate to the expeditionary lead inductor for detecting the video current The current detection device is installed.

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