Power line mounting type current sensor

Abstract

To provide a power line mounting type current sensor capable of minimizing an influence of noise while maintaining high sensitivity at the time of low-current measurement and reducing its size.SOLUTION: A power line mounting type current sensor comprises: a board including an insulating layer and a conductive layer; and a sensor section that is formed so as to pass through the insulating layer and the conductive layer of the board, and includes multiple via holes having a conductive film on an inner wall, and at least one coil formed by line patterning formed so as to electrically connect multiple via holes to the conductive layer. The multiple via holes are formed in two rows lined up in a first direction, the line patterning is formed in conductive layers on both the surfaces of the insulating layer so as to electrically and spirally connect multiple via holes formed in two lined-up rows and form a coil with the first direction as a center axis, and the board is constituted such that a first surface of the board is mounted closer to a power line in a direction that the center axis of the coil crosses the power line that is an object of measurement of current.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power line mounted current sensor. [Background technology]

[0002] Current sensors detect the current flowing through the wire being measured, and are divided into two types depending on their detection method: a resistance detection method that uses a shunt resistor and a magnetic field detection method that uses the magnetic field around the wire. Of these, the magnetic field detection method is divided into sensors that use a current transformer (CT) and sensors that use a Hall element.

[0003] CT elements use the principle of a transformer, so they are primarily used to measure AC currents, which change over time. When a current flows through a conductor, a magnetic field is generated around it, and if a conductor is placed inside a ring-shaped CT, an induced current will flow in the CT coil due to the magnetic field around the conductor.

[0004] A Hall element is an element that utilizes the Hall effect, whereby when a magnetic field is applied in a direction perpendicular to the current, an electromotive force is generated in a direction perpendicular to the current and the magnetic field.Sensors that utilize this Hall effect are called Hall sensors, and they generate a detection signal when the magnetic field of a magnetic object changes.

[0005] Rogowski coil current sensors, another type of magnetic field detection method, measure current by converting the voltage induced in an air-core coil by the AC magnetic field generated around the current being measured. That is, the magnetic field caused by the AC current flowing through the measurement conductor (primary side) interlinks with the air-core coil, generating an induced voltage in the air-core coil. This induced voltage is the time differential of the current being measured, so by passing it through an integrator, a signal proportional to the current being measured is output.

[0006] In yet another method, a current sensor is known in which a sensor unit is positioned at a predetermined distance from a power conductor through which an AC current flows, and the sensor unit measures electromagnetic waves generated by an induced electromotive force generated by the AC current flowing in the power conductor to detect the AC current (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-1981640 [Patent Document 2] Korean Patent Publication No. 10-0897229 Summary of the Invention [Problem to be solved by the invention]

[0008] However, magnetic field detection current sensors have the disadvantage that they cannot be easily attached to existing power lines because the power line passes through the core, and they also require a large mounting area.

[0009] Furthermore, in order to reduce the size of the current sensor, it is possible to consider the current sensor described in Patent Document 1 or a current sensor using a Hall element. However, the current sensor described in Patent Document 1 has a sensor section made up of a non-coil measurement conductor arranged alongside the power conductor, which results in a problem of significantly reduced measurement sensitivity when measuring low currents (for example, 1 A or less).

[0010] Furthermore, since Hall elements require a magnetic core, there are limitations to miniaturization (see, for example, Patent Document 2), and because they react sensitively to magnetic signals, unless they are completely shielded from noise, induced magnetism generated when adjacent power lines are active will flow in as noise, resulting in increased measurement errors.

[0011] Therefore, the present invention has been made in consideration of these points, and aims to provide a power line-mounted current sensor that can minimize the influence of noise while maintaining high sensitivity when measuring low currents, and can reduce the size of the sensor itself.

[0012] The problems to be solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by a person having ordinary skill in the art from the following description. [Means for solving the problem]

[0013] At least one embodiment of the present invention provides a power line-mounted current sensor comprising: a substrate including an insulating layer and conductor layers formed on both sides of the insulating layer; and a sensor unit including a plurality of via holes (Via Hole) formed to penetrate the insulating layer and the conductor layer of the substrate and having a conductive film on an inner wall thereof; and at least one coil formed by line patterning formed to electrically connect the plurality of via holes to the conductor layer, wherein the plurality of via holes are formed in two rows aligned in a first direction, and the line patterning is formed in the conductor layer on both sides of the insulating layer so as to electrically connect the plurality of via holes formed in the two aligned rows in a spiral shape to form the coil with the first direction as a central axis; and the substrate is configured so that a first surface of the substrate is mounted in proximity to a power line in a direction in which the central axis of the coil intersects with the power line whose current is to be measured.

[0014] At least one embodiment of the present invention provides a power line-mounted current sensor comprising: a substrate made of an insulating material; two rows of through holes formed side by side in a first direction in the substrate; and a sensor unit including at least one coil formed by spirally winding an insulating-coated conductor through the two rows of through holes with the coil having a central axis in the first direction, wherein the substrate is configured so that a first surface of the substrate is mounted adjacent to a power line in a direction in which the central axis of the coil intersects with the power line, a current of which is to be measured.

[0015] At least one embodiment of the present invention provides a power line-mounted current sensor comprising: a substrate made of an insulating material; and a sensor unit mounted on the substrate and including at least one coil formed by winding an insulating-coated conductor in a spiral shape around a central axis in a first direction, wherein the substrate is configured so that a first surface of the substrate is mounted in proximity to a power line in a direction in which the central axis of the coil intersects with the power line, the power line being the object of current measurement.

[0016] In at least one embodiment of the present invention, the sensor unit includes a plurality of coils whose central axes are parallel to one another, and the plurality of coils are electrically connected in parallel or in series.

[0017] In at least one embodiment of the present invention, the coil includes an iron core in the center.

[0018] In at least one embodiment of the present invention, the power line-mounted current sensor further includes a shielding case made of a conductive material and configured in a box shape having an opening on a first side, the substrate having L-shaped grooves formed at four corners of a rectangle and opposite sides formed in a cross shape with protruding sides by the length of the L-shaped grooves, the shielding case having recesses formed on both sides of the opening facing the second direction so that both sides of the substrate protruding in a second direction perpendicular to the first direction can be fitted therein, and the substrate is configured such that when both sides protruding in the second direction are fitted into the recesses of the opening, both sides of the substrate in the first direction are inserted into the opening and close the opening.

[0019] In at least one embodiment of the present invention, the power line-mounted current sensor further includes an insulating mounting member configured in a box shape with one side open so that the opening of the shielding case can be inserted therein, the mounting member having a fastening portion on a part of an outer surface thereof to be fixed to the power line.

[0020] In at least one embodiment of the present invention, the power line-mounted current sensor further includes a circuit unit mounted on the substrate, electrically connected to the sensor unit, receiving an output from the coil, and performing predetermined signal processing on the output to output a current signal representing the magnitude of the current flowing through the power line.

[0021] In at least one embodiment of the present invention, the power line-mounted current sensor further includes a circuit unit mounted on a separate board, electrically connected to the sensor unit, receiving an output from the coil, and outputting a current signal representing the magnitude of the current flowing through the power line by performing predetermined signal processing on the output, and the separate board is formed to have the same size as a portion of the board excluding both sides protruding in the second direction, and is fastened to the board with a predetermined fastening member and inserted into the shielding case.

[0022] In at least one embodiment of the present invention, the shielding case includes a power supply port for passing a power line to supply power to the circuit unit and a signal output port for passing a signal output line from the circuit unit.

[0023] In at least one embodiment of the present invention, the power line includes a busbar, and the fastening portion of the mounting member has a rail-shaped groove into which the busbar is inserted and fastened.

[0024] In at least one embodiment of the present invention, the power line includes a busbar, and the fastening portion of the mounting member has a clip-shaped groove into which the busbar is inserted and fastened.

[0025] In at least one embodiment of the present invention, the width of the mounting member in the first direction corresponds to the width of the bus bar, and the width of the board in the first direction is equal to or smaller than the width of the bus bar.

[0026] In at least one embodiment of the present invention, the mounting member is formed such that the inner length in a third direction perpendicular to the first direction and the second direction is equal to the outer length in the third direction of the shielding case.

[0027] In at least one embodiment of the present invention, the mounting member is formed such that an inner length in a third direction perpendicular to the first direction and the second direction is shorter than an outer length in the third direction of the shielding case. [Effects of the Invention]

[0028] According to at least one embodiment of the present invention, it is possible to provide a power line-mounted current sensor that can minimize the influence of noise while maintaining high sensitivity when measuring low currents and can reduce the size of the sensor itself.

[0029] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a perspective view showing a state in which a current sensor according to at least one embodiment of the present invention is attached to a bus bar. [Figure 2] 1A to 1C are a front view, a plan view, a bottom view, a left side view, and a right side view showing a state in which a current sensor according to at least one embodiment of the present invention is attached to a bus bar. [Figure 3] FIG. 1 is a perspective view illustrating a state in which a current sensor according to at least one embodiment of the present invention is attached to a bus bar. [Figure 4] FIG. 1 is an exploded perspective view of a current sensor in accordance with at least one embodiment of the present invention. [Figure 5] 1 is a perspective view of a sensor portion of a current sensor in accordance with at least one embodiment of the present invention; [Figure 6] 1 is a plan view showing a first surface and a second surface of a sensor part of a current sensor in accordance with at least one embodiment of the present invention. [Figure 7] 1 is a perspective view illustrating a coil configuration of a sensor portion of a current sensor in accordance with at least one embodiment of the present invention; [Figure 8] 1 is a side cross-sectional view showing a state in which a current sensor according to at least one embodiment of the present invention is attached to a bus bar. [Figure 9] 1 is an exploded perspective view illustrating the assembly of a current sensor in accordance with at least one embodiment of the present invention. [Figure 10] 1 is a measurement graph for comparing the current sensing performance of a current sensor according to at least one embodiment of the present invention and a current sensor described in Patent Document 1. [Figure 11] 1 is a measurement graph illustrating noise characteristics of a current sensor in accordance with at least one embodiment of the present invention. [Figure 12] 1 is a measurement graph illustrating the non-saturation characteristics of a current sensor in accordance with at least one embodiment of the present invention. [Figure 13] 1 is a perspective view illustrating a coil configuration of a sensor portion of a current sensor in accordance with at least one embodiment of the present invention; [Figure 14] FIG. 1 is an exploded perspective view of a current sensor in accordance with at least one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power line mounted current sensor according to at least one embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0032] FIG. 1 is a perspective view showing a state in which a current sensor 100 according to at least one embodiment of the present invention is attached to a busbar 200. FIG. 2 is a front view, a plan view, a bottom view, a left side view, and a right side view showing a state in which a current sensor 100 according to at least one embodiment of the present invention is attached to a busbar 200. FIG. 3 is a perspective view showing a state in which a current sensor 100 according to at least one embodiment of the present invention is attached to a busbar 200. FIG. 4 is an exploded perspective view of a current sensor 100 according to at least one embodiment of the present invention. FIG. 5 is a perspective view of a sensor unit 110 of a current sensor 100 according to at least one embodiment of the present invention. FIG. 6 is a plan view showing a first surface and a second surface of a sensor unit 110 of a current sensor 100 according to at least one embodiment of the present invention.

[0033] As shown in Figures 1 to 6, a current sensor 100 according to at least one embodiment of the present invention is configured with a sensor unit 110 including a substrate 111 including conductive layers formed on both sides of an insulating layer with the insulating layer sandwiched therebetween, a plurality of via holes (Via HoLe) 112 formed to penetrate the insulating layer and the conductive layer of the substrate 111 and having conductive films 117 formed on their inner walls, and at least one coil C1 to C4 formed with a line patterning 113 formed to connect the plurality of via holes 112 to the conductive layer.

[0034] In at least one embodiment of the present invention, the substrate 111 includes a printed circuit board (PCB) in which insulating layers and conductive layers are stacked to form a substrate, and a desired circuit can be formed through patterning of the conductive layers.

[0035] In at least one embodiment of the present invention, the via holes 112 are formed in two rows aligned in a first direction (the y direction in the example shown in FIG. 5) as shown in FIGS.

[0036] In Figures 5 and 6, the multiple via holes 112 are formed in two rows arranged in a zigzag pattern in the first direction, but as long as the arrangement is such that the multiple via holes 112 can be connected to a spiral coil shape via the line patterning 113 and the multiple via holes 112 can be electrically connected to a spiral coil shape via the line patterning 113, they can also be formed in two rows arranged in a zigzag pattern or in a straight line, and any form is included in the zigzag shape of the present invention.

[0037] 5, a plurality of via holes 112 are arranged at a first position in the X direction, and a plurality of via holes 112 are arranged at a second position in the X direction. The positions in the Y direction of the plurality of via holes 112 at the first position and the positions in the Y direction of the plurality of via holes 112 at the second position are different, but the positions in the Y direction may be the same.

[0038] In other words, when a plurality of via holes 112 are formed in two rows aligned in a straight line in the first direction, one of the rows may have one more or one less via hole as needed. In any case, the line patterning 113 connects the plurality of via holes 112 with diagonal lines on at least one side, so the term "zigzag" is used, and as long as they are formed in two rows side by side, the zigzag and straight lines can be considered to be the same form.

[0039] In at least one embodiment of the present invention, the line patterning 113 is formed in the conductor layers on both sides of the insulating layer so as to electrically connect a plurality of via holes 112 formed in two rows aligned in the above sense in a spiral manner, and form coils C1 to C4 with the first direction as the central axis.

[0040] In at least one embodiment of the present invention, a substrate 111 including at least one coil C1 to C4 formed by a plurality of via holes 112 and line patterning 113 is configured so that a first surface of the substrate 111 is mounted in proximity to a power line (bus bar 200 in the example shown in FIGS. 1 to 3) in a direction in which the central axes of the coils C1 to C4 intersect with the power line whose current is to be measured. The "mounted in proximity" configuration is, for example, a configuration in which the substrate 111 is mounted in contact with the inner wall surface of the current sensor 100 (mounting member 120 in FIG. 4).

[0041] That is, as shown in FIGS. 1 to 4, the current sensor 100 according to at least one embodiment of the present invention is attached to the power line (bus bar 200 in the example shown in FIGS. 1 to 3) as the object of current measurement, without bypassing or cutting the power line, so that the first surface of the sensor unit 110 is adjacent to the power line, and can measure the current flowing through the power line.

[0042] 1 to 4 illustrate a flat bus bar 200 as an example of the power line whose current is to be measured, but the current sensor 100 according to at least one embodiment of the present invention can be applied to any type of power line, including a flat or annular bus bar, a general conductor, etc.

[0043] In at least one embodiment of the present invention, as shown in Figures 5 and 6, the sensor unit 110 includes multiple coils C1 to C4 whose central axes are formed approximately parallel to each other, and the multiple coils C1 to C4 are connected in parallel or in series.

[0044] The sensor unit 110 senses the amount of current flowing through the bus bar 200 based on the induced current induced in the coils C1 to C4, and the greater the amount of induced current, the higher the sensitivity. Therefore, the sensitivity can be improved by connecting the coils C1 to C4, each having a central axis parallel to one another, in parallel to increase the amount of induced current, or by connecting them in series to increase the induced electromotive force.

[0045] 5 and 6 are actual images of the sensor unit 110 manufactured in the above-described manner, in which a plurality of via holes 112 and line patterning 113 are formed on a PCB having a thickness of 2 mm and dimensions of 7 mm x 22 mm in the y and x directions to form a coil C1 with 7 windings, a coil C2 with 5 windings, a coil C3 with 5 windings, and a coil C4 with 7 windings.

[0046] In the sensor unit 110 shown in Figures 5 and 6, the four coils C1 to C4 formed are connected in series with each other and are configured to maximize the induced electromotive force due to the magnetic flux generated by the current flowing through the bus bar 200 in a substrate 111 of a given size.

[0047] FIG. 7 is a perspective view illustrating a coil configuration of the sensor portion 110 of the current sensor 100 in accordance with at least one embodiment of the present invention.

[0048] 7, a conductive film 117 is formed inside a plurality of via holes 112 formed in two rows aligned in a zigzag or straight line in a first direction (y direction) on a substrate 111, and if a line pattern 113 is formed to electrically connect the via holes 112 on both sides in a spiral shape, a coil C1 is formed with a spiral structure between a start point S and an end point E, having an overall length L and a major axis length a, as shown below the arrow in FIG. 7. Here, the minor axis length b of the coil C1 corresponds to the thickness of the substrate 111.

[0049] In at least one embodiment of the present invention, the coils C1 to C4 may include an iron core (not shown) in the center. Coreless coils have the advantage of not being saturated, while coils with iron cores have the disadvantage of being saturated when the magnetic flux density of the iron core reaches its maximum, but have the advantage of improved sensitivity.

[0050] In at least one embodiment of the present invention, the current sensor 100 further includes a box-shaped shielding case 130 made of a conductive (metallic) material having an opening 132 on a first side, as shown in FIG.

[0051] In at least one embodiment of the present invention, the substrate 111 is formed in a cross shape with L-shaped grooves 116 formed at the four corners of a rectangle and with opposing sides protruding by the length of the L-shaped grooves 116 .

[0052] The shielding case 130 has recesses 131 formed on both sides facing the second direction of the opening 132 so that both sides protruding in a second direction (x direction) perpendicular to the first direction of the substrate 111 can be fitted into the recesses 131 of the opening 132, and is configured so that when both sides protruding in the second direction of the substrate 111 are fitted into the recesses 131 of the opening 132, both sides in the first direction are inserted into the opening 132 and block the opening 132.

[0053] Therefore, when the shielding case 130 is attached to the bus bar 200 so that the sensor unit 110 is close to the bus bar 200, the shielding case 130 shields the outer surface of the sensor unit 110 (the opposite side of the bus bar 200), and the bus bar 200 functions to shield the bus bar 200 side.

[0054] With the above-described structure, the sensor unit 110 is shielded on all sides while allowing the magnetic flux generated when current flows through the busbar 200 to enter the interior of the coils C1 to C4 of the sensor unit 110, so the width (length in the first direction) of the sensor unit 110 needs to be set to be equal to or less than the width of the busbar 200.

[0055] In at least one embodiment of the present invention, inside the shielding case 130, the sensor unit 110 is arranged in a direction in which the magnetic flux generated in the bus bar 200 is transmitted most efficiently, so that changes in the magnetism generated in the bus bar 200 can be detected more efficiently.

[0056] In at least one embodiment of the present invention, the current sensor 100 further includes an insulating mounting member 120, which is configured in a box shape with one side open so that the opening 132 side of the shielding case 130 can be inserted, and which has a fastening portion 121 on a part of its outer surface to which the bus bar 200 is fixed, as shown in Figures 1 to 4.

[0057] In the example shown in Figures 1 to 4, a plate-type bus bar 200 bent into an L shape, 2 mm thick and 10 mm wide, is used, and fastening portions 121 are formed on the side of the mounting member 120 to mount the current sensor 100 inserted into the mounting member 120 to the bus bar 200. However, this is one example for explaining the present invention, and by forming fastening portions 121 on the side or bottom of the mounting member 120, the present invention can also be applied to a straight-shaped bus bar, a ring-shaped bus bar, or an electric wire of an appropriate thickness.

[0058] In the example shown in FIGS. 1 to 4, the width of the mounting member 120 is formed to be approximately 11 mm, which is slightly wider than the width of the bus bar 200.

[0059] FIG. 8 is a side cross-sectional view showing a state in which a current sensor 100 according to at least one embodiment of the present invention is attached to a bus bar 200. As shown in FIG.

[0060] As shown in Figure 8, after mounting the substrate 111 on which the sensor unit 110 is formed in the shielding case 130 so as to cover the opening 132, the shielding case 130 is inserted into the mounting member 120 so that the current sensor 100 faces inward, and the current sensor 100 is mounted on the bus bar 200 so that it is close to the bus bar 200. When a current flows through the bus bar 200, the magnetic flux M generated is converted into an induced current as it passes through the coil C of the sensor unit 110.

[0061] That is, the coil C of the sensor unit 110 functions as an induction coil that induces a magnetic flux M that is generated when a current flows through the bus bar 200.

[0062] When an AC current flows through the busbar 200, magnetic flux M generated around the busbar 200 flows inside the coil C, and the resulting change in magnetic flux inside the coil C is converted into an induced current or an induced electromotive force and output via the coil C. Therefore, the amount of current flowing through the busbar 200 can be calculated by calculating such an induced current or an induced electromotive force.

[0063] That is, as shown in Figures 4 and 8, the shielding case 130 includes recesses 131 on both sides facing the second direction of the opening 132 so that both sides protruding in a second direction (x direction) perpendicular to the first direction of the substrate 111 can be fitted into the recesses 131 of the opening 132, and when both sides protruding in the second direction of the substrate 111 are fitted into the recesses 131 of the opening 132, both sides in the first direction are inserted into the opening 132 and block the opening 132. Therefore, when the shielding case 130 is attached to the bus bar 200 so that the sensor unit 110 is close to the bus bar 200, the shielding case 130 shields the outer surface of the sensor unit 110 (the side opposite the bus bar 200), and the bus bar 200 functions to shield the bus bar 200 side.

[0064] That is, in the current sensor 100 according to at least one embodiment of the present invention, when the substrate 111 is attached to the shielding case 130, which is then inserted into the mounting member 120 and attached to the bus bar 200 as shown in FIG. 8, the shielding case 130 and the bus bar 200 shield the sensor unit 110 in all directions, sandwiching the bottom surface of the mounting member 120.

[0065] With the above-described structure, the sensor unit 110 is shielded on all four sides while allowing the magnetic flux generated when current flows through the bus bar 200 to enter the coil C, so the width (length in the first direction) of the sensor unit 110 must be set to be equal to or smaller than the width of the bus bar 200.

[0066] According to the above-described configuration of the present invention, electromagnetic noise transmitted from the bus bar 200 is blocked by the shielding case 130, and magnetic changes occurring in the bus bar 200 are mainly detected by the magnetic flux M transmitted to the sensor unit 110 inside the shielding case 130, thereby minimizing the influence of external noise.

[0067] FIG. 9 is an exploded perspective view illustrating the assembly of a current sensor 100 in accordance with at least one embodiment of the present invention.

[0068] In at least one embodiment of the present invention, the current sensor 100 further includes a circuit unit mounted on the substrate 111, electrically connected to the sensor unit 110, and configured to receive the outputs from the coils C1 to C4 and output a current signal representing the magnitude of the current flowing through the power line through predetermined signal processing.

[0069] In at least one embodiment of the present invention, the circuit unit can calculate the amount of induced current or induced electromotive force output from the sensor unit 110 on the substrate 111 as information and transmit the calculation result to the outside.

[0070] The example shown in FIG. 9 shows a case where the sensor includes a circuit unit mounted on a separate substrate 115, electrically connected to the sensor unit 110, and receiving outputs from the coils C1 to C4 and outputting a current signal representing the magnitude of the current flowing through the power line through predetermined signal processing.

[0071] Here, the separate substrate 115 is formed to have the same size as the portion of the substrate 111 excluding both sides protruding in the second direction, and is fastened to the substrate 111 with a predetermined fastening member and inserted into the shielding case 130.

[0072] Therefore, when the board 111 on which the sensor unit 110 is mounted and the separate board 115 on which the circuit unit is mounted are physically and electrically connected using a predetermined fastening member and inserted into the shielding case 130 in the direction shown in FIG. 9, the separate board 115 is inserted inside the shielding case 130, and the board 111 is mounted in the shielding case 130 so that both sides protruding in the second direction are fitted into the recesses 131 to close the opening 132.

[0073] That is, when the substrate 111 is fitted into the recess 131 of the shielding case 130, the surface L1 of the opening 132 of the shielding case 130 and the outer surface L2 of the current sensor 100 become substantially flush with each other, as shown in FIG.

[0074] In at least one embodiment of the present invention, the current sensor 100 comprises a sensor unit 110 including coils C1 to C4 for sensing the current flowing through the power line, a filter unit connected to the output terminal of the sensor unit 110 for removing noise, and a circuit unit including an amplifier unit (not shown) for amplifying the signal that has passed through the filter unit (not shown).

[0075] The coils C1 to C4 of the current sensor 100 are current sensing units that are attached close to the power lines through which current flows, and output a sinusoidal induced current when a magnetic field generated by the power lines enters the coils.

[0076] The filter section passes the induced current through a low pass filter, passing low frequency signals based on a certain frequency and removing high frequency signals. There is also a filter section at the output end of the amplifier section, and the signal that passed through the amplifier section passes through a high pass filter to remove DC noise and remove signals below a certain frequency.

[0077] The amplifier section amplifies the signal that has passed through the low-pass filter (by approximately 1000 times) using a differential amplifier and outputs a sine wave. The amplification rate can be set as needed.

[0078] In at least one embodiment of the present invention, a signal output terminal 118 for outputting a signal from the circuit unit to the outside and a power supply terminal 119 for supplying power to the circuit unit are electrically connected to the substrate 111 or a separate substrate 115.

[0079] In at least one embodiment of the present invention, the shielding case 130 includes a power supply port (not shown) for passing a power line to supply power to the circuit unit, and a signal output port (not shown) for passing a signal output line from the circuit unit.

[0080] In at least one embodiment of the present invention, the fastening portion 121 of the mounting member 120 has a rail-shaped groove into which the bus bar 200 is inserted and fastened. That is, the current sensor 100 is configured as shown in Figures 4 and 9, and the plate-shaped bus bar 200 is inserted into the rail-shaped groove as shown in Figure 3, and the current sensor 100 is attached to the bus bar 200 so that the sensor portion 110 is close to the bus bar 200 as shown in Figure 1.

[0081] In at least one embodiment of the present invention, the fastening portion 121 of the mounting member 120 has a clip-shaped groove into which the bus bar 200 is inserted and fastened.

[0082] This structure is configured so that, for example, the L-shaped portion that supports the bus bar 200 from the outside at the fastening portion 121 of the mounting member 120 shown in Figure 4 can rotate outward by forming a bent portion (not shown) where it meets the mounting member 120.

[0083] Therefore, for example, the present invention can be used not only for L-shaped bus bars as shown in FIGS. 1 to 3 but also for straight-shaped bus bars or ring-shaped bus bars.

[0084] In at least one embodiment of the present invention, the width of the mounting member 120 corresponds to the width of the bus bar 200 , and the width of the substrate 111 in the first direction is formed to be narrower than the width of the bus bar 200 .

[0085] In at least one embodiment of the present invention, the mounting member 120 is formed so that the inner length in a third direction perpendicular to the first and second directions (the inner length from the opening to the bottom) is equal to the outer length in the third direction of the shielding case 130 (the outer length from the opening to the bottom) (see Figure 8).

[0086] In this way, the current sensor 100 can be configured in which the shielding case 130 including the sensor unit 110 and the circuit unit and the mounting member 120 are integrated together.

[0087] In at least one embodiment of the present invention, the mounting member 120 is formed such that the inner length in a third direction perpendicular to the first and second directions (the inner length from the opening to the bottom) is shorter than the outer length in the third direction of the shielding case 130 (the outer length from the opening to the bottom).

[0088] This structure has the advantage that the shielding case 130 and the mounting member 120 can be easily separated when a problem occurs in the fastening portion 121 of the mounting member 120, or in the sensor unit 110 or the circuit unit.

[0089] FIG. 10 is a measurement graph for comparing the current sensing performance of a current sensor 100 according to at least one embodiment of the present invention and the current sensor described in US Pat. No. 6,249,999.

[0090] As shown in Figure 10, the sensor output for both sensors increases linearly up to 300 A without saturating. However, when the range below 1 A is enlarged, it can be seen that the sensor output of the current sensor 100 according to at least one embodiment of the present invention continues to increase linearly, whereas the sensor output of the current sensor described in Patent Document 1 does not change.

[0091] In other words, the current sensor 100 according to at least one embodiment of the present invention not only exhibits a linear sensor output as the current increases, but also exhibits a linear sensor output even in the low current range of 1 A or less, and therefore has superior advantages in terms of sensitivity.

[0092] FIG. 11 is a measurement graph illustrating noise characteristics of current sensor 100 in accordance with at least one embodiment of the present invention.

[0093] 11 is a graph showing the output voltage waveform of current sensor 100 attached to a power line, measured with an oscilloscope when currents of 0 A and 10 A flow through the power line. Generally, current sensors applied to bus bars contain noise so large that it is difficult to identify the shape of a sine wave when the current is 0 A. However, current sensor 100 according to at least one embodiment of the present invention outputs a clear sine wave even when the current is 0 A, indicating that it is hardly affected by noise.

[0094] FIG. 12 is a measurement graph illustrating the non-saturation characteristics of current sensor 100 in accordance with at least one embodiment of the present invention.

[0095] The graph shown in Fig. 12 compares the characteristics of a commercial CT rated at 40 / 5A and the current sensor 100 according to at least one embodiment of the present invention. When the current flowing through the power line is increased, the current sensor 100 according to at least one embodiment of the present invention exhibits non-saturation characteristics, while the CT exhibits saturation characteristics from around 50A.

[0096] The current sensor 100 shown in Figures 1 to 9 shows an example in which a PCB is used to form a coil through multiple via holes with a conductive film formed on the inner walls and line patterning, but the coil in the sensor section can also be formed from an insulating-coated conductor wire.

[0097] FIG. 13 is a perspective view illustrating a coil configuration of a sensor portion of a current sensor in accordance with at least one embodiment of the present invention.

[0098] As shown in Figure 13, a current sensor according to at least one embodiment of the present invention comprises a substrate 1311 made of an insulating material, two rows of through holes 1312 formed side by side in a first direction (y direction) in the substrate 1311, and a sensor unit including at least one coil C1 formed by spirally winding an insulating coated conductor 1313 through the two rows of through holes 1312 and having a central axis in the first direction.

[0099] In at least one embodiment of the present invention, the substrate 1311 is configured so that a first surface of the substrate 1311 is mounted adjacent to the power line in a direction in which the central axis of the coil C1 intersects with the power line in which the current is to be measured.

[0100] A current sensor according to at least one embodiment of the present invention can have the same structure as the current sensor 100 shown in Figure 6, except that the coil used in the sensor section is formed from an insulating-coated conductor rather than via holes and line patterning.

[0101] FIG. 14 is an exploded perspective view of a current sensor in accordance with at least one embodiment of the present invention.

[0102] As shown in FIG. 14, a current sensor according to at least one embodiment of the present invention comprises a substrate 1411 made of an insulating material and a sensor unit including at least one coil 1412 attached to the substrate 1411 and formed by winding an insulating-coated conductor in a spiral shape around a central axis in a first direction.

[0103] In at least one embodiment of the present invention, the substrate 1411 is configured so that the first surface of the substrate 1411 (in this case the surface on which the coil 1412 is arranged) is mounted adjacent to the power line in a direction in which the central axis of the coil 1412 intersects with the power line in which the current is to be measured.

[0104] The current sensor shown in FIG. 14 further includes a circuit portion 1414 mounted on a substrate 1411 and a shielding case 1430 .

[0105] In at least one embodiment of the present invention, the sensor portion comprises a coil 1412 that functions as an induction coil and may optionally include an iron core 1413 .

[0106] As shown in FIG. 14, shielding case 1430 is formed in a box shape having opening 1431 on one side, and is made of a conductive material so as to prevent external electromagnetic noise from penetrating into the interior.

[0107] Bus bar 1400, for example, connects power sources between lines, and as shown in FIG. 14, covers opening 1431 of shielding case 1430 and is fastened to shielding case 1430.

[0108] That is, the shielding case 1430 has an internal storage space, and the bus bar 1400 serves as a cover, forming a sealed chamber. To this end, the shielding case 1430 is formed with a fastening portion 1433 having a through hole 1434 for fastening to the bus bar 1400, and the bus bar 1400 is formed with a through hole 1410.

[0109] The sensor section of the current sensor shown in FIG. 14 is configured with coil 1412, which is an induction coil that converts the magnetic flux generated when a current flows through bus bar 1400 into an induced current and induces the magnetic flux of bus bar 1400.

[0110] With this structure, when an AC current flows through busbar 1400, magnetic flux generated around busbar 1400 flows inside coil 1412, and the resulting change in magnetic flux inside coil 1412 is converted into an induced current or induced electromotive force and output in coil 1412. Therefore, the amount of current flowing through busbar 1400 can be calculated by calculating this induced current or induced electromotive force.

[0111] According to the above-described configuration of the present invention, electromagnetic noise transmitted from outside the bus bar 1400 is blocked by the shielding case 1430, and magnetic changes generated in the bus bar 1400 are transmitted to the sensor unit as magnetic flux inside the shielding case 1430, thereby minimizing the effects of external noise.

[0112] As described above, the sensor unit senses the amount of current flowing through bus bar 1400 based on the induced current induced in coil 1412, and the greater the amount of induced current, the higher the sensitivity. Therefore, in at least one embodiment of the present invention, a plurality of coils 1412 included in the sensor unit can be provided within shielding case 1430 as shown in FIG.

[0113] In this case, an induced current is generated in each coil 1412, so the amount of induced current can be increased by connecting them in parallel, or the induced electromotive force can be increased by connecting them in series, thereby improving sensitivity.

[0114] In at least one embodiment of the present invention, a terminal through hole 1432 is formed on one side of the shielding case 1430, and the output terminal 1415 of the substrate 1411 protrudes through the terminal through hole 1432 and is configured to seal the inside of the shielding case 1430.

[0115] Like the current sensor shown in Figure 13, the current sensor shown in Figure 14 can have the same structure as the current sensor 100 shown in Figure 6, except that the coil used in the sensor section is formed from an insulating-coated conductor on a substrate.

[0116] As described above, according to at least one embodiment of the present invention, it is possible to provide a power line-mounted current sensor that can minimize the influence of noise while maintaining high sensitivity when measuring low currents and can reduce the size of the sensor itself.

[0117] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention. [Explanation of symbols]

[0118] 100: Current sensor 110: Sensor section 111: Substrate 112: Beer Hall (Via HoLe) 113: Track patterning 114: Sensor output terminal 115: Separate board (circuit part) 116:L-shaped groove 117: Conductive film 118: Signal output terminal 119: Power supply terminal 120: Mounting material 130: Shielding case 131: Recess 1311: Circuit board 1312:Through hole 1313: Insulated conductor 1400: Busbar 1411: Circuit board 1412: Coil 1413: Iron core 1414:Circuit section 1430: Shielding case 1431: Opening 1433: Fastening part C, C1, C2, C3, C4: Coils M: magnetic flux

Claims

1. a substrate including an insulating layer and conductor layers formed on both sides of the insulating layer; a sensor unit including a plurality of via holes (Via HoLe) formed to penetrate the insulating layer and the conductor layer of the substrate and having a conductive film on an inner wall thereof, and at least one coil formed by line patterning formed to electrically connect the plurality of via holes to the conductor layer; Equipped with the plurality of via holes are formed in two rows aligned in a first direction, the line patterning is formed in the conductor layers on both sides of the insulating layer so as to electrically connect the via holes formed in the two adjacent rows in a spiral shape to form the coil with the first direction as a central axis, the substrate is configured so that a first surface of the substrate is mounted in proximity to a power line in a direction in which the central axis of the coil intersects with the power line in which a current is to be measured, Power line mounted current sensor.

2. a substrate made of an insulating material; two rows of through holes formed side by side in a first direction in the substrate; a sensor unit including at least one coil in which an insulating-coated conductor is wound spirally through the two rows of through holes and has a central axis in the first direction; Equipped with the substrate is configured so that a first surface of the substrate is mounted in proximity to a power line in a direction in which the central axis of the coil intersects with the power line in which a current is to be measured, Power line mounted current sensor.

3. a substrate made of an insulating material; a sensor unit mounted on the substrate and including at least one coil formed by winding an insulating-coated conductor in a spiral shape around a central axis in a first direction; Equipped with the substrate is configured so that a first surface of the substrate is mounted in proximity to a power line in a direction in which the central axis of the coil intersects with the power line in which a current is to be measured, Power line mounted current sensor.

4. the sensor unit includes a plurality of coils whose central axes are parallel to one another, The plurality of coils are electrically connected in parallel or in series.

4. The power line mounted current sensor according to claim 1.

5. The coil includes an iron core at the center.

4. The power line mounted current sensor according to claim 1.

6. The device further includes a box-shaped shielding case made of a conductive material and having an opening on the first side, The substrate is formed in a cross shape with L-shaped grooves formed at four corners of a square and with opposing sides protruding by the length of the L-shaped grooves, the shielding case has recesses formed on both sides of the opening facing the second direction so that both sides of the board protruding in a second direction perpendicular to the first direction can be fitted therein; the substrate is formed such that when both sides protruding in the second direction are fitted into the recesses of the opening, both sides in the first direction are inserted into the opening and close the opening; 4. The power line mounted current sensor according to claim 1.

7. a mounting member made of an insulating material, the mounting member having a box shape with one open side so that the opening of the shielding case can be inserted therein, and a fastening portion on a part of an outer surface of the mounting member that is fastened to the power line; The power line mounted current sensor according to claim 6.

8. a circuit unit mounted on the substrate, electrically connected to the sensor unit, receiving an output from the coil, and performing predetermined signal processing on the output to output a current signal representing the magnitude of the current flowing through the power line; The power line mounted current sensor according to claim 6.

9. a circuit unit mounted on a separate board, electrically connected to the sensor unit, receiving an output from the coil, and performing predetermined signal processing on the output to output a current signal representing the magnitude of a current flowing through the power line; The separate board is formed to have the same size as the board except for both sides protruding in the second direction, and is fastened to the board by a predetermined fastening member and inserted into the shielding case. The power line mounted current sensor according to claim 6.

10. the shielding case includes a power supply port for passing a power line for supplying power to the circuit unit and a signal output port for passing a signal output line from the circuit unit.

10. The power line mounted current sensor according to claim 8 or 9.

11. The power line includes a busbar, the fastening portion of the mounting member has a rail-shaped groove into which the bus bar is inserted and fastened. The power line mounted current sensor according to claim 7.

12. The power line includes a busbar, the fastening portion of the mounting member has a clip-shaped groove into which the bus bar is inserted and fastened. The power line mounted current sensor according to claim 7.

13. a width of the mounting member in the first direction corresponds to a width of the bus bar; The width of the substrate in the first direction is equal to or less than the width of the bus bar. The power line mounted current sensor according to claim 11 or 12.

14. The mounting member has an inner length in a third direction perpendicular to the first direction and the second direction, the inner length being equal to an outer length in the third direction of the shielding case. The power line mounted current sensor according to claim 7.

15. The mounting member has an inner length in a third direction perpendicular to the first direction and the second direction that is shorter than an outer length in the third direction of the shielding case. The power line mounted current sensor according to claim 7.

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