Current sensor assembly

Abstract

The present invention relates to a current sensor assembly, which includes: a housing; a plurality of shields accommodated inside the housing and opening upward toward the housing; a plurality of busbars to which three-phase currents are applied and arranged at intervals to respectively pass through the plurality of shields; and a current sensor unit including a printed circuit board and a plurality of current sensors arranged on the printed circuit board, the current sensors measuring the currents applied to the busbars; the shields, the busbars, and the current sensor unit are accommodated inside the housing; the current sensors are arranged at intervals from the busbars and are arranged inside the internal space of the shields.

Description

Technical Field

[0001] The present invention relates to a current sensor assembly included in an inverter. Background Art

[0002] In recent years, the technological development of electric vehicles that run using electric energy as a green energy source has been rapidly progressing. An electric vehicle refers to a vehicle that runs using electric energy, and can be roughly classified into a battery-powered electric vehicle and a hybrid electric vehicle.

[0003] Among them, a battery-powered electric vehicle runs only using electric energy, and is usually referred to as an electric vehicle. In addition, a hybrid electric vehicle refers to a vehicle that runs using electric energy and fossil fuel.

[0004] Most electric vehicles include a motor that generates a rotational force, a battery that supplies power to the motor, an inverter that controls the rotational speed of the motor, a battery charger for charging the battery, and a vehicle low-voltage DC conversion device (LDC: Low-voltage DC / DC Converter).

[0005] Among them, the inverter has a sensor that senses current to precisely control the motor.

[0006] However, the existing sensor for sensing current is configured separately from the bus bar. Specifically, the bus bar, the current sensor, and the shield are combined into at least two or more components. Therefore, there is a problem that an error occurs when the current sensor measures the current flowing in the bus bar.

[0007] In addition, since the bus bar, the current sensor, and the shield are combined into at least two or more components, there is a problem that it is difficult to organically change the positional relationship of the bus bar, the current sensor, and the shield. Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The first object of the present invention is to provide a current sensor assembly capable of combining a bus bar, a current sensor, and a shield into one component.

[0010] The second object of the present invention is to provide a current sensor assembly capable of optimizing the relative positions and distances of the bus bar, the current sensor, and the shield.

[0011] Technical Solutions for Solving the Problems

[0012] To achieve the object of the present invention as described above, the above-described current sensor assembly includes: a housing; a plurality of shields accommodated inside the housing and opening upward toward the housing; a plurality of busbars to which three-phase currents are applied and arranged separately from each other to pass through the shields respectively; and a current sensor unit including a printed circuit board and a plurality of current sensors arranged on the printed circuit board, the current sensors measuring the currents applied to the busbars; the plurality of shields, the plurality of busbars, and the current sensor unit are accommodated inside the housing; the current sensors are arranged separately from the busbars and arranged in the internal space of the shields.

[0013] As another example, it may further include a housing cover arranged at the upper end of the housing to cover the inside of the housing, and the housing cover may include a support protrusion extending downward from the housing cover and contacting the printed circuit board.

[0014] As another example, the current sensors may be arranged separately from each other on the printed circuit board, and grooves through which the shields pass may be formed on the printed circuit board.

[0015] As another example, the shield may include: an inner portion arranged inside the housing; and protrusions protruding from both sides of the inner portion; the busbar may be arranged close to the inner portion and pass through the shield; the current sensors may be arranged between the protrusions; inside the housing, the direction in which the busbar is separated from the shield and passes above the inner portion of the shield may form a first axis, the direction in which the inner portion of the shield extends may form a second axis, and the direction in which the protrusions extend from both ends of the shield may form a third axis.

[0016] As another example, the shield is configured such that the volume of the shield calculated from the width, length of the shield, and the height of the protrusion enables the numerical range of the current applied to the busbar measured by the current sensor to be included in the range of the current flowing in the busbar within a range that can ensure linearity.

[0017] As another example, the shield and the busbar may be separated by a first distance in the direction of the third axis so that the numerical range of the current applied to the busbar measured by the current sensor can ensure linearity within the range of the current flowing in the busbar.

[0018] As another example, the current sensors may be separated from the busbar by a second distance in the direction of the third axis so that the currents measured by the current sensors within the range of the current flowing in the busbar remain linear.

[0019] As another example, a plurality of current sensors respectively corresponding to a plurality of busbars constituting the three phases may be arranged close to the center between the protruding portions surrounding each current sensor in the shield.

[0020] As another example, the current sensor may be arranged at a third distance from the surface of the inner side portion of the shield along a third axis.

[0021] As another example, the current sensor may be arranged at a fourth distance from the center of the busbar in the direction of the second axis.

[0022] As another example, the current sensor may be arranged at a predetermined distance from the surface of the busbar along the third axis direction.

[0023] Advantages of the Invention

[0024] The effects of the present invention obtained by the above solutions are as follows.

[0025] Since the support protruding portion of the housing cover contacts the printed circuit board, it is possible to reduce the vibration of the current sensor in the current sensor portion caused by the vibration of the current sensor assembly following the vibration of the inverter during inverter driving. Thereby, it is possible to reduce the error that may occur due to the vibration of the current sensor when detecting the current applied to the busbar.

[0026] It is possible to easily grasp the volume of the shield that is optimal for the current sensor to linearly detect the current flowing in the busbar. And, according to the positional relationship between the center of the busbar and the current sensor, it is easy to grasp the range in which the current sensor can linearly detect, and the positions of the busbar and the current sensor can be further optimized.

[0027] By measuring and considering various crosstalk effects of the current sensor located between the protruding portions of the shield on the first axis to the third axis, it is easier to grasp the position of the current sensor that minimizes the crosstalk effect caused by adjacent busbars, and by adjusting the positions of the current sensor and the shield, it is possible to more accurately detect the current flowing in the busbar.

[0028] Considering that the magnetic flux density changes according to the skin effect of the busbar, the current sensor is arranged close to the busbar and close to the end of the busbar, thereby being able to minimize the phase delay effect caused by the magnetic flux density difference to the maximum extent.

[0029] Avoid the molding portion from overly surrounding the protruding portion so that most of the area of the protruding portion is exposed from the molding portion. Thereby, the width w between the protruding portions is maintained, and thus the volume of the shield and the shielding ability of the shield can be kept constant. Description of the Drawings

[0030] Figure 1 This is a diagram showing an integrated power device according to an embodiment of the present invention.

[0031] Figure 2 This is a diagram showing an inverter assembly according to an embodiment of the present invention.

[0032] Figure 3 This is Figure 2 an exploded perspective view showing the exploded inverter assembly.

[0033] Figure 4 and Figure 5 These are diagrams for explaining the direction of current flow in the inverter assembly.

[0034] Figure 6 This is a diagram showing a current sensor assembly according to an embodiment of the present invention.

[0035] Figure 7 and Figure 8 This is Figure 6 an exploded perspective view showing the exploded current sensor assembly.

[0036] Figure 9 This is a diagram for explaining that a housing cover combined with the back surface of the housing and a support protrusion protruding from the housing cover support a printed circuit board.

[0037] Figure 10 This is for explaining Figure 6 a cross-sectional view of the current sensor assembly.

[0038] Figure 11 and Figure 12 These are diagrams for explaining the range of current that can be measured by the current sensor according to the bus bar, the position of the current sensor, and the volume of the shield.

[0039] Figure 13 and Figure 14 These are diagrams for explaining the crosstalk generated in one current sensor according to the relative position of the shield and the current sensor.

[0040] Figure 15 and Figure 16 These are diagrams for explaining the skin effect and phase delay generated according to the frequency of the current flowing in the bus bar.

[0041] Figure 17 and Figure 18 These are diagrams for explaining the positions and distances of the shield, the bus bar, and the current sensor portion.

[0042] Figure 19 This is a diagram for explaining the molding portion for fixing the shield and the bus bar inside the housing. Detailed Description

[0043] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the accompanying drawings. The same or similar components are given the same reference numerals regardless of the figure numbers, and repeated descriptions thereof will be omitted. In the following description, the suffixes "module" and "section" for components are given or used interchangeably only for the convenience of writing the specification, and they do not have meanings or functions that distinguish each other. In addition, in the process of describing the embodiments disclosed in this specification, if it is determined that the detailed description of related well-known technologies makes the gist of the embodiments disclosed in this specification unclear, the detailed description thereof will be omitted. In addition, the drawings are provided for the convenience of understanding the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited to the drawings. The present invention includes all changes, equivalents, and substitutes made within the technical idea and technical scope of the present invention.

[0044] Terms including ordinals such as "first" and "second" may be used to describe various components, but the components are not limited by the terms. The terms are only used to distinguish one component from another.

[0045] If it is mentioned that a certain component is "connected" or "coupled" to another component, it should be understood that it may be directly connected or coupled to the other component, but there may also be other components in between. Conversely, if it is mentioned that a certain component is "directly connected" or "directly coupled" to another component, it should be understood that there are no other components between them.

[0046] Unless the context clearly indicates otherwise, singular expressions include plural expressions.

[0047] In this application, terms such as "including" or "having" are only used to specify the existence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and are not intended to exclude the existence or possibility of addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0048] Figure 1 It is a diagram showing an integrated power device according to an embodiment of the present invention. Figure 2 It is a diagram showing an inverter assembly according to an embodiment of the present invention. Figure 3 It is to Figure 2 The exploded perspective view of the inverter assembly shown decomposed. Figure 4 and Figure 5 It is a diagram for explaining the current flow direction in the inverter assembly.

[0049] Refer to Figure 1, shows an integrated power supply device 1000. The integrated power supply device 1000 may include an auxiliary power supply unit (APM Assembly), a charging module, an inverter assembly 1, and a BDU assembly that distributes power to each module. The integrated power supply device 1000 is surrounded by a top cover assembly 1001 and an integrated module housing 1002.

[0050] Referring to Figure 2 and Figure 3 , shows the inverter assembly 1 included in the integrated power supply device 1000. The inverter assembly 1 is configured to control the current supplied to the motor, and may include: a large-capacity capacitor 10 that stores energy (electric power) for driving the inverter, a DC bus bar assembly 20, a control board 30, a gate board 40, a top compression member 50, a power module assembly 60, and a bottom compression member 70.

[0051] In addition, the current C1 supplied from the large-capacity capacitor 10 to the motor may be transmitted to the bus bar via the power semiconductor module B. In this process, the current flowing through the bus bar may flow through the current sensor assembly A.

[0052] Figure 6 is a diagram showing a current sensor assembly according to an embodiment of the present invention. Figure 7 and Figure 8 are exploded perspective views showing the current sensor assembly of Figure 6 exploded. Figure 9 is a diagram for explaining a case where a case cover combined with the back surface of the case and a support protrusion protruding from the case cover support a printed circuit board. Figure 10 is for explaining Figure 6 cross-sectional view of the current sensor assembly.

[0053] Referring to Figure 6 , the current sensor assembly A according to an embodiment of the present invention is disposed on a path where current flows from a large-capacity capacitor 10 that stores energy (electric power) for driving the inverter to the bus bar assembly 390. The large-capacity capacitor 10, the current sensor assembly A, and the bus bar assembly 390 may be disposed in combination with the case H.

[0054] Referring to Figure 7 , the current sensor assembly A according to an embodiment of the present invention includes a case 100, a shield 200, a bus bar 300, and a current sensor unit 400.

[0055] The case 100 has a substantially quadrilateral cross-section. An internal space 120 that can accommodate the shield 200, the bus bar 300, and the current sensor unit 400 may be formed in the case 100. The shield 200, the bus bar 300, and the current sensor unit 400 may be sequentially accommodated in the internal space 120 from bottom to top.

[0056] The housing 100 may further include a housing cover 500. The housing cover 500 may be coupled to the upper end of the housing 100 to cover the internal space 120 of the housing 100.

[0057] Specifically, the housing 100 may be formed with a housing groove 110h on its back surface. In addition, the housing cover 500 may include a fixing protrusion 530 that extends downward from the housing cover body 510 and is inserted into the housing groove 110h. As Figure 9 shown, if the housing cover 500 is configured to cover the internal space 120 of the housing 100, the fixing protrusion 530 of the housing cover 500 is engaged with the housing groove 110h, so that the housing 100 and the housing cover 500 can be combined.

[0058] The housing cover 500 may include a support protrusion 520 that extends downward from the housing cover body 510 and contacts the printed circuit board 420.

[0059] Specifically, as Figure 7 shown, the support protrusion 520 protrudes downward from the housing cover body 510. In addition, as Figure 9 shown in (c), when the housing cover 500 is combined with the housing 100, the support protrusion 520 may contact the printed circuit board 420.

[0060] To this end, the support protrusion 520 may be formed to be slightly larger than the distance h1 between the inner side surface of the housing cover body 510 and the printed circuit board 420. For example, the support protrusion 520 may be formed to be about 2 mm longer than the distance h1 between the inner side surface of the housing cover body 510 and the printed circuit board 420.

[0061] Since the support protrusion 520 supports the printed circuit board 420, it is possible to reduce the vibration of the current sensor 410 of the current sensor unit 400 caused by the vibration of the current sensor assembly A as the inverter vibrates during inverter driving. Thus, it is possible to reduce the error that may occur due to the vibration of the current sensor 410 when measuring the current applied to the bus bar 300.

[0062] A plurality of shielding members 200 are provided. The plurality of shielding members 200 may be accommodated inside the housing 100, and each may be configured to open upward toward the housing 100.

[0063] The shielding member 200 includes an inner side portion 210 disposed inside the housing 100 and protruding portions 220 protruding from both sides of the inner side portion 210. At this time, the portion where three surfaces of the shielding member 200 are not surrounded and are open is disposed upward with respect to the housing 100. It should be noted that the installation direction of the housing 100 may be changed according to the design.

[0064] At this time, the inside of the shielding member 200 refers to the area surrounded by the inner portion 210 and the protruding portion 220 of the shielding member 200. In addition, the area formed by the inside of the shielding member 200 can be regarded as the volume of the shielding member 200. The volume of such a shielding member 200 is related to the magnitude of the current measured by the current sensor 410 disposed inside the shielding member 200. This will be described in detail later. The bus bar 300 is configured to pass through the inside of the shielding member 200.

[0065] A plurality of bus bars 300 are provided. Three-phase currents are respectively applied to the plurality of bus bars 300. The bus bar 300 is disposed close to the inner portion 210, and the plurality of bus bars 300 are spaced apart from each other to respectively pass through the plurality of shielding members 200.

[0066] Specifically, as Figure 7 shown, the plurality of bus bars 300 may include a first bus bar 300a, a second bus bar 300b, and a third bus bar 300c. Currents of different phases from each other may flow in each of the bus bars 300a, 300b, and 300c. For example, a U-phase current may flow in the first bus bar 300a, a V-phase current may flow in the second bus bar 300b, and a W-phase current may flow in the third bus bar 300c.

[0067] Specifically, the power module including the large-capacity capacitor 10 can provide three-phase power by providing three-phase currents to drive a motor.

[0068] The three-phase power includes three symmetric sine waves whose phases are 120 degrees electrical angle apart from each other. For example, in a symmetric three-phase power supply system, with respect to a common reference, three conductors respectively transmit alternating currents with the same frequency and voltage amplitude but with a phase difference of 1 / 3 cycle. Due to the phase difference, the voltage on any conductor reaches its peak 1 / 3 cycle after one conductor and 1 / 3 cycle before the remaining conductor among the other conductors. This phase delay provides a constant power transmission to a balanced linear load. In addition, a rotating magnetic field can be generated in an electric motor, and other phase arrays can be generated using a transformer.

[0069] The current sensor unit 400 may include a printed circuit board 420 and a plurality of current sensors 410.

[0070] A plurality of current sensors 410 are provided and arranged on the printed circuit board 420. The current sensors 410 measure the current flowing in the bus bar 300. Depending on their types, the magnitudes of the currents that the current sensors 410 can measure may be different. For example, a current sensor 410 that can measure a magnetic flux density of 60 mT can be used. The current sensor 410 can also measure a magnetic flux density exceeding 60 mT, or can also measure a magnetic flux density less than 60 mT.

[0071] The current sensors 410 are arranged separately from the bus bar 300 and are arranged in the internal space 120 of the shield 200. The current sensors 410 are arranged between the protruding portions 220 of the shield 200. Specifically, referring to Figure 7 , the shield 200 is inserted into the interior of the housing 100. In addition, the bus bar 300 is arranged to pass above the shield 200. In addition, the current sensor unit 400 is arranged at a predetermined distance from the bus bar 300. At this time, the current sensors 410 are arranged in a region surrounded by three sides in the shield 200.

[0072] The current sensors 410 are arranged separately from each other on the printed circuit board 420.

[0073] On the printed circuit board 420, a groove through which the shield 200 can pass may be formed. Specifically, as Figure 7 shown, a first groove 422 through which the shield 200 can pass may be formed on the printed circuit board 420.

[0074] In addition, a second hole 424 into which a fixing protrusion 540 protruding from the housing cover 500 is inserted may be formed on the printed circuit board 420. The printed circuit board 420 can be fixed to the internal space 120 of the housing by the fixing protrusion 540. In addition, a molding portion md may be formed in the internal space 120 of the housing 100 to fix the housing 100, the shield 200, and the bus bar 300.

[0075] In the current sensor assembly A according to an embodiment of the present invention, by stacking and fixing the shield 200, the bus bar 300, and the current sensor unit 400 inside a single housing 100, it is possible to reduce errors that may occur when separated into two or more components. In addition, by arranging the shield 200, the bus bar 300, and the current sensor unit 400 close to each other in the internal space 120 of a single housing, it is possible to design to minimize various problems that may occur when the current sensors 410 measure current.

[0076] Figure 11 and Figure 12 are diagrams for explaining the range of currents that the current sensor can measure according to the bus bar, the position of the current sensor, and the volume of the shield.

[0077] The volume of the shielding member 200 according to an embodiment of the present invention can be within a range that enables the value range of the current applied to the bus bar 300 measured by the current sensor 410 to form a current range flowing through the bus bar 300 within a range that can ensure linearity. This is to select the volume of the shielding member 200 within the magnetic field range measurable by the current sensor 410.

[0078] First, the volume of the shielding member 200 can be calculated from the width, length of the shielding member 200, and the height of the protruding portion 220. Specifically, referring to Figure 11 of (c), the volume of the shielding member 200 can be the product of the width w, length l of the shielding member 200, and the height h of the protruding portion 220.

[0079] Referring to Figure 11 of (a), the magnetic flux density corresponding to lines a to d measured by the current sensor 410 according to the volume of the shielding member 200 is represented on the vertical axis of the figure. Specifically, lines a to d represent the magnetic flux density measured by the current sensor 410 according to the width size of the shielding member 200 when the length of the shielding member 200 and the height of the protruding portion 220 are the same. In addition, the horizontal axis of the figure represents the current applied to the bus bar 300.

[0080] For example, line a represents the case where the width of the shielding member 200 is about 15 mm, line b represents the case where the width is about 20 mm, line c represents the case where the width is about 25 mm, and line d represents the case where the width is about 30 mm.

[0081] On the other hand, lines e to f are the magnitudes of the magnetic flux density measured on the inner surface of the shielding member 200 when the width between the inner portions 210 of the shielding member 200 is about 15 mm, 20 mm, 25 mm, and 30 mm. If the current exceeds about 1200 A, the magnetic flux density in all four cases drops sharply.

[0082] The current sensor 410 can have a maximum magnetic flux density required for linearly measuring the current applied to the bus bar 300 according to its size and performance. For example, if the current sensor 410 has a product name of MLX91208CAV, when the current applied to the bus bar 300 is about 1200 A, the measured magnetic flux density can be from about 50 mT to about 100 mT according to the width size of the shielding member 200.

[0083] However, the above-mentioned current sensor 410 can linearly measure up to about 60 mT. Therefore, preferably, the width between the inner portions 210 of the shield 200 is about 25 mm or about 30 mm. Additionally, the volume of the shield 200 can be selected within the range where such a current sensor 410 can linearly measure the current applied to the bus bar 300. In this example, lines c and d can be selected.

[0084] The definitions of the first axis to the third axis inside the housing 100 are as follows.

[0085] The first axis is the direction in which the bus bar 300 is spaced apart from the shield 200 and passes over the inner portions 210 of the shield 200. For example, referring to Figure 12 (a) of, the first axis is the x-axis direction. The second axis is the direction in which the inner portions 210 of the shield 200 extend. Referring to Figure 12 (a) of, the second axis is the y-axis direction. The third axis is the direction in which the protruding portions 220 extend from both ends of the shield 200. Referring to Figure 12 (a) of, the third axis is the z-axis direction.

[0086] The shield 200 and the bus bar 300 can be spaced apart by a first distance in the third axis direction so that the numerical range of the current applied to the bus bar 300 measured by the current sensor 410 can ensure linearity within the range of the current flowing in the bus bar 300. Specifically, in Figure 11 (b) of, the distance from the inner portion 210 of the shield 200 to the bus bar 300 can be referred to as the first distance in the third axis direction. Later, referring to Figure 17 and Figure 18 , it will be described in detail.

[0087] Additionally, the current sensor 410 can be spaced apart from the bus bar 300 by a second distance in the third axis direction so that the current measured by the current sensor 410 within the range of the current flowing in the bus bar 300 remains linear. Specifically, in Figure 11 (b) of, the distance c from the surface of the bus bar 300 to the center portion 415 of the current sensor can be regarded as the second distance in the third axis direction.

[0088] Referring to Figure 12 , it shows the amount of current measured by the current sensor 410 according to the changes in the first axis to the third axis due to the relative positions of the bus bar 300 and the center portion 415 of the current sensor.

[0089] First, referring to Figure 12(a) shows the magnetic flux density measured by the current sensor 410 at each position when the central portion 415 of the current sensor is arranged at different positions along the first axis (x-axis) from the first position 415a as a reference on the bus bar 300.

[0090] When the current sensor 410 is located at the first position 415a, the second position 415b, and the third position 415c, the magnetic flux density measured by the current sensor 410 at each position is the a-line, the b-line, and the c-line, respectively. At this time, the magnetic flux density measured by the current sensor 410 at the first position 415a, the second position 415b, and the third position 415c shows almost no difference.

[0091] Refer to Figure 12 (b) shows the magnetic flux density measured by the current sensor 410 at each position when the central portion 415 of the current sensor is arranged at different positions along the second axis (y-axis) from the first position 415a as a reference on the bus bar 300. At this time, the magnetic flux density measured by the current sensor 410 at the first position 415a, the second position 415b, and the third position 415c shows almost no difference.

[0092] Refer to Figure 12 (c) shows the magnetic flux density measured by the current sensor 410 at each position when the central portion 415 of the current sensor is arranged at different positions along the third axis (z-axis) from the first position 415a as a reference on the bus bar 300. At this time, the first position 415a is the position where the central portion 415 of the current sensor is separated from the bus bar 300 by a reference distance, the second position 415b is the position where the central portion 415 of the current sensor is far from the bus bar 300, and the third position 415c is the position where the central portion 415 of the current sensor is arranged closer to the bus bar 300 than the first position 415a.

[0093] At this time, when the central portion 415 of the current sensor is arranged at the third position 415c closer to the bus bar 300 than the first position 415a, when a current of about 1200 A flows in the bus bar 300, the magnetic flux density measured by the current sensor 410 may exceed 60 mT. This is because the closer the central portion 415 of the current sensor is arranged to the bus bar 300, the stronger the magnetic field generated by the current flowing in the bus bar 300. Therefore, in terms of the magnetic range, preferably, the central portion 415 of the current sensor is separated from the bus bar 300 by a specified distance instead of being arranged too close.

[0094] An advantage of the current sensor assembly A according to an embodiment of the present invention is that it is possible to easily determine the optimal volume of the shield 200 in which the current sensor 410 can linearly measure the current flowing in the bus bar 300. Moreover, the advantage also lies in that, based on the positional relationship between the bus bar 300 and the central portion 415 of the current sensor, it is easy to determine the range in which the current sensor 410 can linearly measure, and the positions of the bus bar 300 and the current sensor 410 can be further optimized.

[0095] Figure 13 And Figure 14 is a diagram for explaining crosstalk generated in one current sensor according to the relative positions of the shield and the current sensor.

[0096] Referring to Figure 13 , the bus bar 300 may include a first bus bar 300a, a second bus bar 300b, and a third bus bar 300c in which a U-phase current, a V-phase current, and a W-phase current flow, respectively. At this time, the current sensors 410 disposed on the first bus bar 300a, the second bus bar 300b, and the third bus bar 300c may measure the currents flowing in the adjacent bus bars 300a, 300b, and 300c among the bus bars 300a, 300b, and 300c. This may be referred to as crosstalk.

[0097] In order to minimize such crosstalk, preferably, a plurality of current sensors 410 respectively corresponding to the plurality of bus bars 300a, 300b, and 300c constituting three phases are disposed adjacent to the center between the protruding portions 220 surrounding the respective current sensors 410 in the shield 200.

[0098] Specifically, referring to Figure 14 of (a), it shows the degree of crosstalk generated by the current sensor 410 at each position when the central portion 415 of the current sensor is disposed at different positions along the first axis (x-axis) from the first position 415a which is a reference between the protruding portions 220 of the shield 200.

[0099] At this time, g1 to g4 represent the crosstalk effects between the first bus bar 300a and the second bus bar 300b, the crosstalk effects between the first bus bar 300a and the third bus bar 300c, and the crosstalk effects between the second bus bar 300b and the third bus bar 300c. In addition, the crosstalk effects generated in the a region, the b region, and the c region respectively represent the crosstalk effects generated at the first position 415a, the second position 415b, and the third position 415c.

[0100] When the current sensor 410 is at the first position 415a, the second position 415b, and the third position 415c between the protruding portions 220 of the shield 200, the crosstalk effects of each current sensor 410 generated at each position do not vary significantly. However, the crosstalk effect at the first position 415a, which is the reference position, is the smallest. Therefore, when the current sensor 410 is arranged at the first position 415a along the first axis between the protruding portions 220, the crosstalk effect is the smallest.

[0101] Refer to Figure 14 of (b), which shows the degree of crosstalk generated by the current sensor 410 at each position when the central portion 415 of the current sensor is arranged at different positions along the second axis (y-axis) from the first position 415a, which is the reference between the protruding portions 220 of the shield 200.

[0102] Compared with the first position 415a, the crosstalk effect of the central portion 415 of the current sensor is greater at the second position 415b and the third position 415c. As a result, the current sensor 410 cannot measure the accurate current value of the corresponding bus bar 300. Therefore, when the current sensor 410 is arranged at the first position 415a along the second axis between the protruding portions 220, the crosstalk effect is the smallest.

[0103] Refer to Figure 14 of (c), which shows the degree of crosstalk generated by the current sensor 410 at each position when the central portion 415 of the current sensor is arranged at different positions along the third axis (z-axis) from the first position 415a, which is the reference between the protruding portions 220 of the shield 200.

[0104] It can be confirmed that the crosstalk effect increases as the central portion 415 of the current sensor approaches the first position 415a and the third position 415c from the second position 415b. This is because as the central portion 415 of the current sensor moves away from the inner portion 210 of the shield 200, the shielding effect of the protruding portions 220 of the shield 200 on the current sensor 410 decreases. As a result, the current sensor 410 may be more affected by the current flowing in the adjacent bus bar 300. Therefore, when the current sensor 410 is arranged at the second position 415b along the third axis between the protruding portions 220, the crosstalk effect is the smallest.

[0105] That is, preferably, the current sensor 410 is arranged to be spaced apart from the surface of the inner portion 210 of the shield 200 by a third distance along the third axis. Later, refer to Figure 17 and Figure 18Describe the third distance in detail. The advantage of the current sensor assembly A according to an embodiment of the present invention is that by measuring and considering various crosstalk effects of the current sensor 410 located between the protrusions 220 of the shield 200 on the first to third axes, it is easier to grasp the position of the current sensor 410 that minimizes the crosstalk effect generated by the adjacent bus bars 300, and by adjusting the positions of the current sensor 410 and the shield 200, it is possible to measure more accurately the current flowing in the bus bar 300.

[0106] Figure 15 And Figure 16 is a diagram for explaining the skin effect and phase delay generated according to the frequency of the current flowing in the bus bar.

[0107] Figure 15 The upper diagram of [Figure number] shows the magnetic flux density generated at each position of the bus bar 300 according to the frequency of the current flowing in the bus bar 300. Refer to Figure 15 The upper diagram of [Figure number], as the frequency of the current increases, the magnetic flux density in the central region 301 of the bus bar 300 drops sharply. In addition, as the frequency of the current increases, the magnetic flux density in the outer region 302 of the bus bar 300 increases significantly. This can be referred to as the skin effect.

[0108] In addition, Figure 15 The lower diagram of [Figure number] shows the phase delay generated at each position of the bus bar 300 according to the frequency of the current flowing in the bus bar 300. As described above, if the frequency of the current increases, the magnetic flux density in the central region 301 of the bus bar 300 will drop sharply, and thus, the higher the frequency, the greater the phase delay in the central region 301 of the bus bar 300 may be than the phase delay in the outer region 302 of the bus bar 300.

[0109] To reduce the above-mentioned phase delay, the current sensor 410 may be configured to be separated from the center in the second axis direction of the bus bar 300 by a fourth distance.

[0110] Specifically, referring to Figure 16 the (a) of [Figure number], it shows the degree of phase delay generated by the current sensor 410 at each position when the central portion 415 of the current sensor is arranged at different positions along the first axis (x-axis) from the first position 415a as a reference on the bus bar 300. The a region, b region, and c region respectively represent the degree of phase delay generated at the first position 415a, the second position 415b, and the third position 415c.

[0111] If the current sensor 410 moves along the first axis, it is equivalent to moving along the central region of the bus bar 300. Therefore, the phase delays at the first position 415a, the second position 415b, and the third position 415c are the same. Therefore, in terms of phase delay, the position of the current sensor 410 along the first axis from the first position 415a is not restricted within a specified distance.

[0112] Referring to Figure 16 (b) of, shows the degree of phase delay generated by the current sensor 410 at each position when the central portion 415 of the current sensor is arranged at different positions along the second axis (y-axis) from the first position 415a as a reference on the bus bar 300.

[0113] At this time, as the central portion 415 of the current sensor moves along the second axis from the first position 415a, the central portion 415 of the current sensor can move from the central region 301 of the bus bar 300 toward the outer region 302. As described above, since the magnetic flux density is high and the phase delay is small in the outer region 302 of the bus bar 300, the phase delay can be reduced as the current sensor 410 moves from the first position 415a as a reference to the second position 415b and the third position 415c.

[0114] Therefore, preferably, in order to reduce the phase delay effect, the central portion 415 of the current sensor, that is, the current sensor 410 moves along the second axis on the bus bar 300.

[0115] On the other hand, preferably, the current sensor 410 is arranged at a specified distance from the surface of the bus bar 300 in the direction of the third axis.

[0116] Specifically, referring to Figure 16 (c) of, shows the degree of phase delay generated by the current sensor 410 at each position when the central portion 415 of the current sensor is arranged at different positions along the third axis (z-axis) from the first position 415a as a reference on the bus bar 300.

[0117] It can be confirmed that if the current sensor 410 moves from the first position 415a as a reference to the third position 415c arranged closer to the bus bar 300, the phase delay is reduced. In addition, it can be confirmed that if the current sensor 410 moves from the first position 415a to the second position 415b, the phase delay becomes larger. This is because if the current sensor 410 is arranged closer to the bus bar 300, the magnetic flux density of the bus bar 300 increases, thereby reducing the phase delay effect generated in the current sensor 410.

[0118] Therefore, in order to reduce the phase delay effect, preferably, the central portion 415 of the current sensor is moved in the third axis direction on the bus bar 300 toward the direction approaching the bus bar 300.

[0119] However, as described above, if the current sensor 410 is configured to be too close to the bus bar 300, the magnetic flux density becomes too high and may exceed the magnetic flux density that the current sensor 410 can linearly measure. Therefore, it is necessary to set a distance that can reduce the phase delay while satisfying the magnetic flux density condition measurable by the current sensor 410.

[0120] An advantage of the current sensor assembly A according to an embodiment of the present invention is that, considering that the magnetic flux density varies according to the skin effect of the bus bar 300, the current sensor 410 is disposed close to the bus bar 300 and close to the end of the bus bar 300, thereby being able to minimize the phase delay effect caused by the magnetic flux density difference.

[0121] Figure 17 and Figure 18 is a diagram for explaining the positions and distances of the shield, the bus bar, and the current sensor unit.

[0122] As described above, the shield 200, the bus bar 300, and the current sensor 410 may be separated by a predetermined distance in the first axis direction to the third axis direction.

[0123] Specifically, the shield 200 and the bus bar 300 may be separated by a first distance in the third axis direction so that the numerical range of the current applied to the bus bar 300 measured by the current sensor 410 can ensure linearity within the range of the current flowing through the bus bar 300. Refer to Figure 17 , the first distance may be referred to as g.

[0124] In addition, the current sensor 410 may be separated from the bus bar 300 by a second distance in the third axis direction so that the current measured within the range of the current flowing through the bus bar 300 remains linear. Refer to Figure 17 , the second distance may be referred to as c.

[0125] In addition, the current sensor 410 may be configured to be separated from the surface of the inner portion 210 of the shield 200 by a third distance in the third axis. Refer to Figure 17 , the third distance may be the distance obtained by adding g, b, and c.

[0126] In addition, in order to reduce the phase delay, the current sensor 410 may be configured to be separated from the center of the bus bar 300 in the second axis direction by a fourth distance. Refer to Figure 17 , the fourth distance may be referred to as f (refer to Figure 18 (a)).

[0127] The following describes the preferred distance considering all of the above-mentioned magnetic range measurable by the current sensor 410, crosstalk effect, and phase delay effect when the thickness t of the inner portion 210 of the shield 200 is set to 3 mm.

[0128] Preferably, the width w between the protruding portions 220 of the shield 200 is about 25 mm. Preferably, the height h of the protruding portions 220 of the shield 200 is about 18 mm. Preferably, the inner distance h' between the shields 200 is about 20 mm.

[0129] Preferably, the lateral length a of the bus bar 300 is about 14 mm. Preferably, the thickness b of the bus bar 300 is about 3 mm. Preferably, the distance c from the surface of the bus bar 300 to the central portion 415 of the current sensor is about 4.7 mm. Preferably, the distance i between the surface of the bus bar 300 and the inner surface of one of the protruding portions 220 is about 2 mm. Preferably, the distance j between the bus bar 300 and an adjacent bus bar 300 is about 51 mm. Preferably, the distance g from the lower surface of the bus bar 300 to the surface of the inner portion 210 of the shield 200 is about 2 mm.

[0130] Preferably, the distance d from the central portion 415 of the current sensor to the upper end portion of the protruding portion 220 is about 8.3 mm. Preferably, the distance e from the central portion 415 of the current sensor to the inner surface of the protruding portion 220 is about 12.5 mm. Preferably, the distance k between the central portion 415 of the current sensor and the side end portion of the shield 200 is about 4 mm. Preferably, the distance f between the central portion 415 of the current sensor and the central portion of the bus bar 300 is about 3.5 mm.

[0131] It should be noted that the preferred distances between the above-mentioned respective components can be changed according to the volume of the shield 200, the measurement ability of the current sensor 410, the magnitude and frequency of the current applied to the bus bar 300.

[0132] On the other hand, Figure 18 (b) shows the bus bar 300 according to another embodiment of the present invention.

[0133] Referring to Figure 18 (b), the width of the bus bar 300 can be greater than that of the above embodiment. Specifically, the width of the bus bar 300 can be reduced in the section passing through the shield 200. Thereby, the magnetic flux density of the bus bar 300 in the section passing through the shield 200 can be further increased.

[0134] Specifically, when the width a of the section where the bus bar 300 passes through the shielding member 200 is set to 14 mm, the width a' of the bus bar 300 before and after passing through the shielding member 200 can be greater than 14 mm, for example, it can be 16 mm to 18 mm. For this purpose, a bus bar protrusion 305 can be formed. In addition, a bus bar recessed groove 300' can be formed between the bus bar protrusions 305.

[0135] However, in this embodiment as well, the phase delay effect decreases in the outer region of the bus bar 300. Therefore, preferably, the current sensor 410 is arranged on the end side of the bus bar 300.

[0136] Figure 19 It is a diagram for explaining a molding portion for fixing a shielding member and a bus bar inside a housing.

[0137] The shielding member 200 and the bus bar 300 of an embodiment of the present invention can be fixed by a molding portion md inside the housing 100. Specifically, a molding portion md can be formed in the internal space 120 of the housing to fix the positions of the shielding member 200 and the bus bar 300 after the shielding member 200 and the bus bar 300 are arranged in the internal space 120 of the housing.

[0138] However, as Figure 19 shown in (a) of, if the molding portion md is formed to surround most of the protrusion 220 of the shielding member 200, the following problem may occur: during the process in which the molding portion md, which is a liquid, solidifies into a solid, a force f such as a force generated by thermal expansion force and thermal contraction force may be generated. Under the action of such a force, the protrusion 220 may receive the force from the molding portion md.

[0139] Under the action of the force received by the protrusion 220 from the molding portion md, a torque tq, which is a bending force, can be generated in the protrusions 220 on both sides. Under the action of such a torque tq, the protrusions 220 can move away from or close to each other. Therefore, the size of the width w between the protrusions 220 changes. If the size of the width w between the protrusions 220 changes, the overall volume of the shielding member 200 may change. As a result, it may affect the magnetic flux density sensed by the current sensor 410.

[0140] Referring to Figure 19 (b) of, the molding portion md can be formed not to cover the protrusion 220 of the shielding member 200. Thus, the protrusion 220 is not affected by the thermal expansion force and thermal contraction force generated when the molding portion md hardens, so that the size of the width w between the protrusions 220 can remain the same.

[0141] In addition, referring to Figure 19In (c) thereof, the height a at which the protruding portion 220 is surrounded by the molding portion md can be formed to be less than 50% of the overall height b of the protruding portion 220. Therefore, it is possible to maximize the force with which the molding portion md fixes the shielding member 200 while reducing the torque tq generated in the protruding portion 220 due to the force generated when the molding portion md hardens.

[0142] An advantage of the current sensor assembly A according to an embodiment of the present invention is that the molding portion md is prevented from overly surrounding the protruding portion 220 so that most of the area of the protruding portion 220 is exposed from the molding portion md. As a result, the width w between the protruding portions 220 is maintained, and thus the volume of the shielding member 200 and the shielding ability of the shielding member 200 can be kept constant.

[0143] The current sensor assembly as described above is not limited to the configurations and methods of the above-described embodiments, but can be configured by selectively combining all or a part of each embodiment to form the above-described embodiments, and thus various modifications can be made.

Claims

1. A current sensor assembly Among them, including: a housing; a plurality of shielding members accommodated inside the housing and opening upward toward the housing; a plurality of busbars to which three-phase currents are applied and arranged separately from each other to pass through the shielding members respectively; and a current sensor unit including a printed circuit board and a plurality of current sensors arranged on the printed circuit board, the current sensors measuring the current applied to the busbars; the plurality of shielding members, the plurality of busbars, and the current sensor unit are accommodated inside the housing; the current sensors are arranged separately from the busbars and are arranged in the internal space of the shielding members; the shielding member includes: an inner portion arranged inside the housing; and protrusions protruding from both sides of the inner portion; the busbar is arranged close to the inner portion and penetrates the shielding member; the current sensors are arranged between the protrusions; inside the housing, the direction in which the busbar is separated from the shielding member and passes above the inner portion of the shielding member constitutes a first axis, the direction in which the inner portion of the shielding member extends constitutes a second axis, and the direction in which the protrusions extend from both ends of the shielding member constitutes a third axis; a plurality of current sensors respectively corresponding to the plurality of busbars constituting the three phases are arranged at the center between the protrusions surrounding each current sensor in the shielding member; the center of the busbar is separated from the center between the protrusions of the shielding member by a preset fourth distance along the second axis direction.

2. The current sensor assembly according to claim 1, wherein, further including: a housing cover arranged at the upper end of the housing to cover the inside of the housing; the housing cover includes: a support protrusion extending downward from the housing cover and contacting the printed circuit board.

3. The current sensor assembly according to claim 1, wherein, the current sensors are arranged separately from each other on the printed circuit board, grooves through which the shielding members penetrate are formed on the printed circuit board.

4. The current sensor assembly according to claim 1, wherein, the shielding member is configured such that the volume of the shielding member is calculated from the width, length of the shielding member, and the height of the protrusion, so that the numerical range of the current applied to the busbar measured by the current sensor is included in the current range flowing in the busbar within a range where linearity can be ensured.

5. The current sensor assembly according to claim 4, wherein, the shielding member and the busbar are separated by a first distance along the third axis direction, so that the numerical range of the current applied to the busbar measured by the current sensor can ensure linearity within the current range flowing in the busbar.

6. The current sensor assembly according to claim 5, wherein, the current sensors are separated from the busbars by a second distance along the third axis direction, so that the current measured by the current sensors within the current range flowing in the busbars remains linear.

7. The current sensor assembly according to claim 1, wherein, The current sensor is configured to be separated from the surface of the inner portion of the shield by a third distance along a third axis.

8. The current sensor assembly according to claim 1, wherein the current sensor is configured to be separated from the center of the bus bar in the second axis direction by a fourth distance.

9. The current sensor assembly according to claim 8, wherein the current sensor is configured to be separated from the surface of the bus bar by a predetermined distance along the third axis direction.

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