JP6802098B2 - Current sensor - Google Patents

Description

The present specification relates to a current sensor. In particular, the present invention relates to a current sensor in which a magnetron conversion element is adjacent to at least one of two conductors extending in parallel, and the two conductors and the magnetron conversion element are sandwiched between a pair of shield plates.

The above-mentioned current sensor is disclosed in, for example, Patent Document 1. The magnetic-electric conversion element measures the magnetic flux generated around the conductor due to the current flowing through the conductor to be measured. Based on the predetermined relationship between the magnetic flux and the current, the magnitude of the current flowing through the conductor can be specified from the magnitude of the measured magnetic flux.

For convenience of explanation, the conductor of interest for which the electromagnetic conversion element of interest measures the current is referred to as a target conductor, and the conductor that is not the target conductor is referred to as a non-target conductor. In addition, the following coordinate system will be introduced as a coordinate system for explanation. The X-axis of the coordinate system is defined as the extending direction of the conductors, the Y-axis is defined as the arrangement direction of the plurality of conductors, and the directions orthogonal to the X-axis and the Y-axis are defined as the Z-axis. Further, for convenience, the magnetic flux generated around the conductor due to the current flowing through the conductor will be referred to as "magnetic flux generated by the conductor". Further, in the present specification, the non-target conductor is also referred to as a current sensor.

In order to reduce the influence of the magnetic flux generated by the non-target conductor, the magnetoelectric conversion element is arranged adjacent to the target conductor in the Z direction. The pair of shield plates sandwich a plurality of conductors and a magnetic-electric conversion element in the Z direction in order to block noise magnetic flux from the outside.

Japanese Unexamined Patent Publication No. 2016-038203

As described above, the shield plate is provided to block the magnetic flux from the outside. However, a part of the magnetic flux generated by the asymmetric conductor passes through the shield plate. The magnetic flux flows in an annular shape so as to surround the asymmetric conductor. A diagram illustrating the magnetic flux is shown in FIG. FIG. 12 is a cross-sectional view of the current sensor 102 cut at a cross section orthogonal to the X-axis. The current sensor 102 includes a first conductor 103 which is a target conductor, a second conductor 104 which is a non-target conductor, a magnetron conversion element 105, and shield plates 106 and 107. The magnetic-electric conversion element 105 measures the magnetic flux Bt generated by the first conductor 103 (target conductor), and a processing circuit (not shown) converts the measured magnetic flux magnitude into a current value and outputs the measured magnetic flux. The magnetron conversion element 105 is arranged in a posture in which the magnetic sensing direction faces the Y direction. The arrow Sd in the figure indicates the magnetic sensing direction of the magnetron conversion element 105. When a current flows through the second conductor 104 from the front side to the back side of the paper surface, the magnetic flux generated by the second conductor 104 flows clockwise around the second conductor 104 so as to surround the second conductor 104. The magnetic flux generated by the second conductor 104 flows through the upper shield plate 106 from left to right, and flows from the upper shield plate 106 to the lower shield plate 107 near the right end of the upper shield plate 106. The magnetic flux flows through the lower shield plate 107 from right to left, and flows cyclically from the lower shield plate 107 to the upper shield plate 106 near the left end. When the current flows from the back side to the front side of the paper surface, the magnetic flux flows in the opposite direction to the above direction. The thick line Bn in FIG. 12 represents the magnetic flux generated by the second conductor 104. When the facing surfaces of the shield plates 106 and 107 are parallel, as shown by the thick line Bn, the magnetic flux is curved so as to swell in the direction away from the second conductor 104 between the pair of shield plates 106 and 107. The magnetic flux Bn generated by the second conductor 104 has a Y-direction component, that is, a magnetic-sensing direction component when crossing the magnetic-electric conversion element 105 (in the magnetic flux Bn, the Y-direction component is present at the location indicated by the arrow Ax). The portion indicated by the reference numeral R in the drawing indicates the angle of incidence on the upper shield plate 106 of the magnetic flux Bn. The magnetic-electric conversion element 105 measures a part of the magnetic flux (noise magnetic flux Bn) generated by the second conductor 104, and the accuracy of the current measurement value of the first conductor (target conductor) is lowered. The present specification provides a technique for suppressing a decrease in current measurement accuracy due to a magnetic flux generated by a second conductor (non-target conductor) in a current sensor in which at least two conductors are sandwiched between a pair of shield plates.

The current sensor disclosed in the present specification includes a first conductor, a second conductor, a magnetron conversion element, and a pair of shield plates. The first conductor and the second conductor extend in parallel along the X direction (first direction). The first conductor and the second conductor are arranged in the Y direction (second direction). The magnetron conversion element is adjacent to the first conductor in the Z direction (third direction). The magnetron conversion element is arranged so that its magnetic sensing direction faces the Y direction (second direction). The pair of shield plates sandwich the first conductor, the second conductor, and the magnetron conversion element in the Z direction (third direction). The shield plate on the side close to the magnetron conversion element at least has a surface facing the first and second conductors whose surface facing the magnetron conversion element is inclined toward the second conductor.

In the current sensor disclosed in the present specification, the range of the surface of the shield plate close to the magnetron conversion element facing the magnetron conversion element is inclined toward the non-target conductor (first conductor). Due to this inclination, the direction of the magnetic flux (noise magnetic flux) generated by the asymmetric conductor in the magnetic-electric conversion element shifts toward the Z direction. As a result, the Y-direction component of the noise magnetic flux at the position of the magnetic-electric conversion element, that is, the magnetic-sensing direction component is reduced, and the influence of the noise magnetic flux is reduced. Details of the techniques disclosed herein and further improvements will be described in the "Modes for Carrying Out the Invention" below.

It is sectional drawing explaining the operation effect of the current sensor disclosed in this specification. It is a circuit diagram of the power converter to which the current sensor of an Example is applied. It is a top view of the power converter. It is a perspective view of a current sensor. It is sectional drawing along the VV line of FIG. It is sectional drawing of the current sensor of the 1st modification. It is sectional drawing of the current sensor of the 2nd modification. It is sectional drawing of the current sensor of the 3rd modification. It is sectional drawing of the current sensor of the 4th modification. It is a perspective view of the current sensor of the 5th modification. It is sectional drawing along the line XI-XI of FIG. It is sectional drawing explaining the flow of the magnetic flux in the conventional current sensor.

The principle of the current sensor 2 disclosed in the present specification will be described with reference to FIG. The current sensor 2 has the simplest configuration for explaining the principle of the technique disclosed herein. FIG. 1 is a cross-sectional view of the current sensor 2. In all the figures, the meaning of each axis of the coordinate system is as described above. FIG. 1 is a cross-sectional view of the current sensor 2 cut along a plane orthogonal to the X-axis. The current sensor 2 includes a conductor to be measured for current (first conductor 3), a second conductor 4 which is a non-target conductor, an electromagnetic conversion element 5, and a pair of shield plates (upper shield plate 6 and lower shield plate 7). Although not shown, the pair of shield plates 6 and 7 and the magnetron conversion element 5 are embedded in the resin body. The first conductor 3 and the second conductor 4 penetrate the resin body.

The first conductor 3 (target conductor) and the second conductor 4 (non-target conductor) extend in parallel along the X direction. The magnetron conversion element 5 is arranged adjacent to the first conductor 3 in the Z direction. The magnetron conversion element 5 is arranged in a posture in which the magnetic sensing direction faces the Y direction. The arrow Sd in the figure indicates the magnetic sensing direction. The magnetic-electric conversion element 5 mainly measures the magnetic flux Bt generated by the first conductor 3. The magnetic flux measured by the magnetic-electric conversion element 5 is sent to a processing circuit (not shown). In the processing circuit, the magnitude of the current flowing through the first conductor 3 is specified based on the magnitude of the measured magnetic flux. The pair of shield plates 6 and 7 sandwich the first conductor 3, the second conductor 4, and the magnetron conversion element 5 in the Z direction. The facing surfaces of the pair of shield plates 106 and 107 of the conventional current sensor 102 were flat (see FIG. 12). On the other hand, in the current sensor 2, the magnetron conversion element 5 and the lower surface of the upper shield plate 6 (the surface facing the first conductor 3 and the second conductor 4), which is closer to the magnetron conversion element 5 than the lower shield plate 7. The facing range (element facing range 6a) is tilted toward the non-target conductor 4.

In FIG. 1, the thick line Bn represents the magnetic flux (noise magnetic flux Bn) generated by the second conductor 4. Between the pair of shield plates 6 and 7, the noise magnetic flux Bn is curved so as to swell in a direction away from the second conductor 4. On the side close to the magnetron conversion element 5, the incident angle R of the noise magnetic flux Bn with respect to the upper shield plate 6 is substantially the same as the incident angle R in FIG. 12 of the comparative example. However, since the element facing range 6a of the upper shield plate 6 is tilted toward the second conductor 4, the direction of the noise magnetic flux Bn when the noise magnetic flux Bn crosses the magnetic-electric conversion element 5 is close to the Z direction (FIG. 1). Refer to the part indicated by the symbol Ay of). As a result, the Y-direction component of the noise magnetic flux Bn when the noise magnetic flux Bn crosses the magnetic-electric conversion element 5 becomes smaller than in the case of the conventional example (FIG. 12). That is, the influence of the noise magnetic flux Bn on the measured value of the magnetron conversion element 5 becomes small. Compared with the conventional current sensor 102 of FIG. 12, the current sensor 2 suppresses a decrease in current measurement accuracy due to the magnetic flux (noise magnetic flux) generated by the second conductor 4 (non-target conductor).

The element facing range 6a may not be flat but may be curved. When the element facing range 6a is curved, "the element facing range 6a is tilted toward the second conductor 4" means a plane extending in the Y direction through the magnetic electroconversion element 5 (plane Ha in FIG. 1). The distance (distance dH in FIG. 1) with respect to the element facing range 6a in the Z direction may gradually increase as it approaches the second conductor 4.

The current sensor of the embodiment will be described with reference to FIGS. 2 to 5. First, the power converter to which the current sensor is applied will be described. FIG. 2 shows a circuit diagram of the power converter 20. The power converter 20 is a device that converts the DC power of the battery 52 into the drive power of the traveling motor (motor 23) in the electric vehicle. The power converter 20 includes a voltage converter 21 that boosts the voltage of the battery 52 and an inverter 22 that converts the boosted DC power into AC power. The voltage converter 21 includes a filter capacitor 53, a reactor 54, two transistors 56a and 56b, and two diodes. The two transistors 56a and 56b are connected in series. Diodes are connected in anti-parallel to each of the transistors 56a and 56b. The series connection of the transistors 56a and 56b is connected in series to the high voltage end (terminal on the inverter side) of the voltage converter 21. One end of the reactor 54 is connected to the midpoint of the series connection of the two transistors 56a and 56b. The other end of the reactor 54 is connected to the positive electrode at the low voltage end (terminal on the battery side) of the voltage converter 21. A filter capacitor 53 is connected between the positive electrode and the negative electrode at the low voltage end. The voltage converter 21 of FIG. 2 boosts the voltage of the battery 52 and supplies it to the inverter 22, and steps down the power sent from the inverter 22 (regenerated power generated by the motor 23) to charge the battery 52. Both operations can be performed. The voltage converter 21 is a so-called bidirectional DC-DC converter. Since the circuit configuration and function of the voltage converter 21 of FIG. 2 are well known, detailed description thereof will be omitted.

The inverter 22 has a configuration in which three sets of two transistors connected in series are connected in parallel. Transistors 56c and 56d are connected in series, transistors 56e and 56f are connected in series, and transistors 56g and 56h are connected in series. Diodes are connected in anti-parallel to each transistor. Alternating current is output from the midpoint of the three sets of series connections. The AC output of the inverter 22 is supplied to the motor 23. Since the circuit configuration and operation of the inverter 22 of FIG. 2 are well known, detailed description thereof will be omitted. A smoothing capacitor 57 is connected in parallel between the voltage converter 21 and the inverter 22. The smoothing capacitor 57 suppresses the pulsation of the current flowing between the voltage converter 21 and the inverter 22.

The power converter 20 includes a current sensor 10 that simultaneously measures the currents of two phases of the three-phase AC output of the inverter 22. The current sensor 10 is a unit in which magnetron conversion elements 11a and 11b are installed in the vicinity of two of the three bus bars connecting between the output terminal of the inverter 22 and the output terminal of the power converter 20. is there. The bus bar is a conductor of a metal elongated plate (slender bar) suitable for transmitting a large current with low loss. The measurement data of the current sensor 10 is sent to the controller 59. The controller 59 estimates the current of the remaining one phase from the measured value of the current of the two phases. The controller 59 receives the target output of the motor 23 from an upper controller (not shown), and drives the transistors 56a-56h while feeding back the measured value of the current sensor 10 so that the target output is realized. In FIG. 1, the broken line arrow indicates the signal line. The signal lines from the controller 59 to the transistors 56a and 56b are shown, but the signal lines to the transistors 56c-56h are not shown.

FIG. 3 shows a plan view of the hardware of the power converter 20. The eight transistors 56a-56h of the power converter 20 are housed in two card-type semiconductor modules 31a-31d each. The two transistors 56a, 56b (and diode) of the voltage converter 21 are housed in the semiconductor module 31a. The two transistors 56a and 56b are connected in series inside the semiconductor module 31a. The diode is connected in antiparallel to each of the transistors 56a and 56b inside the semiconductor module 31a. The series connection of the transistors 56c and 56d is housed in the semiconductor module 31b, the series connection of the transistors 56e and 56f is housed in the semiconductor module 31c, and the series connection of the transistors 56g and 56h is housed in the semiconductor module 31d. .. The four semiconductor modules 31a-31d are laminated with a plurality of flat plate type coolers 32 to form a stacking unit 37. In FIG. 3, reference numerals 32 are attached only to the coolers at both ends of the laminated unit 37, and the reference numerals are omitted for the coolers between them. The four semiconductor modules 31a-31d and the plurality of coolers 32 are alternately laminated one by one. Each of the semiconductor modules 31a-31d is cooled from both sides thereof. The laminating unit 37 is housed in the housing 30 while being pressurized in the laminating direction between the inner wall of the housing 30 and the leaf spring 39.

An output terminal extends from the upper surface of each semiconductor module 31a-31d. The terminal 33 is a terminal that conducts to the midpoint of the series connection of the two transistors. The terminal 33 of the semiconductor module 31a is connected to one end of the reactor 54 via the bus bar 35. Each of the terminals 33 of the semiconductor modules 31b-31d is connected to the output terminals 34 provided on the outside of the housing 30 via the bus bars 13a-13c. A power cable extending from the motor 23 is connected to the output terminal 34. The magnetron conversion element 11a is arranged so as to be adjacent to the bus bar 13a, and the magnetron conversion element 11b is arranged so as to be adjacent to the bus bar 13b. As described above, the magnetic-electric conversion elements 11a and 11b constitute a current sensor 10 that simultaneously measures the magnetic flux corresponding to each of the two-phase currents of the three-phase AC output of the inverter 22.

A capacitor unit 38 is arranged adjacent to the stacking unit 37. The capacitor unit 38 houses the filter capacitor 53 and the smoothing capacitor 57 described with reference to FIG. As shown in FIG. 2, in all the series connections of the two transistors, the high potential side terminal and the low potential side terminal are connected in parallel to the smoothing capacitor 57. In FIG. 3, the other terminals of the semiconductor modules 31a-31d, that is, the bus bars connecting the terminals on the high potential side and the low potential side of the series connection of the two transistors and the smoothing capacitor 57 are not shown. ..

The magnetic-electric conversion element 11a of the current sensor 10 measures the magnetic flux generated by the current flowing through the bus bar 13a to be measured (the magnetic flux generated by the bus bar 13a). The magnetic-electric conversion element 11b measures the magnetic flux generated by the current flowing through the bus bar 13b to be measured (the magnetic flux generated by the bus bar 13b). The current sensor 10 specifies the magnitude of the current flowing through the bus bar from the magnitude of the measured magnetic flux. On the other hand, as described above, the bus bars 13a-13c and 35 are arranged inside the housing 30 of the power converter 20, and the reactor 54 having the coil 54a is housed. They generate noise magnetic flux due to the switching operation of the transistors 56a-56h housed in the semiconductor modules 31a-31d. The noise magnetic flux reduces the current measurement accuracy of the current sensor 10. Therefore, the current sensor 10 includes a shield plate that protects the magnetic and electrical conversion elements 11a and 11b from external noise magnetic flux. Next, the structure of the current sensor 10 including the shield plate will be described.

FIG. 4 shows a perspective view of the current sensor 10. The current sensor 10 includes bus bars 13a and 13b through which a current to be measured is passed, magnetron conversion elements 11a and 11b corresponding to the respective bus bars, a pair of shield plates (upper shield plate 14 and shield plate 15), and a resin mold 16. And a data processing circuit (not shown) is provided. The current sensor 10 also includes a bus bar 13c other than the bus bars 13a and 13b to be measured for current.

The coordinate system is shown after FIG. As described above, the X-axis of the coordinate system extends in the extending direction of the bus bars 13a-13c, the Y-axis extends in the alignment direction of the plurality of bus bars 13a-13c, and the Z-axis is the X-axis. And the Y axis are orthogonal to each other. Notches 12a and 12b are provided in the bus bars 13a and 13b, respectively, and the magnetron conversion elements 11a and 11b are arranged in the notches of the bus bars, respectively. The notches 12a and 12b are arranged at the same position when viewed from the Y direction. When the notch is provided in the bus bar, the current is concentrated in the remaining part of the notch in the bus bar, and the density of the magnetic flux generated in the surroundings is increased. By arranging the magnetron conversion element 11a (11b) in the notch 12a (12b), the magnetic flux density measured by the magnetron conversion element 11a (11b) is increased, and the current measurement accuracy is improved.

The upper shield plate 14 and the lower shield plate 15 are arranged so as to sandwich the bus bar 13a-13c and the magnetron conversion elements 11a and 11b in the Z direction. The space between the shield plates 14 and 15 is filled with the resin mold 16. That is, the magnetron conversion elements 11a and 11b are embedded in the resin mold 16. In FIG. 4, the resin mold 16 is shown in gray to aid understanding. The surfaces of the upper shield plate 14 and the lower shield plate 15 facing the magnetron conversion elements 11a and 11b are inclined. The shield plates 14 and 15 will be described below.

A cross-sectional view taken along the line VV of FIG. 4 is shown in FIG. In FIG. 5, priority is given to the legibility of the figure, and the hatching representing the cross section of the resin mold 16 is omitted. The magnetic-electric conversion element 11a measures the magnetic flux Bt generated by the current flowing through the bus bar 13a (the magnetic flux Bt generated by the bus bar 13a). The measured magnetic flux Bt is converted into the magnitude of the current flowing through the bus bar 13a and output by a data processing circuit (not shown). For the magnetron conversion element 11a, the bus bar 13a is the target conductor, and the bus bars 13b and 13c correspond to the non-target conductors.

The magnetron conversion element 11a is adjacent to the bus bar 13a in the Z direction, and at the position of the magnetron conversion element 11a, the magnetic flux Bt to be measured faces in the Y direction. The magnetron conversion element 11a is arranged so that its magnetic sensing direction Sd faces the Y direction, and the magnetic flux Bt generated by the bus bar 13a can be accurately measured. However, the bus bars 13b and 13c are non-target conductors for the magnetic-electric conversion element 11a, and the magnetic flux generated by these bus bars is a noise magnetic flux. The magnetic flux generated by the bus bars 13b and 13c passes through the upper shield plate 14 and the lower shield plate 15 and reciprocates between the upper shield plate 14 and the lower shield plate 15. As described above with reference to FIG. 1, the upper shield plate 14 has a range (element facing range 14a) facing the magnetron conversion element 11a among the surfaces facing the bus bar 13a-13c. It is tilted toward the asymmetric conductors (bass bars 13b, 13c). Similarly, of the surfaces of the lower shield plate 15 facing the bus bar 13a-13c, the range facing the magnetron conversion element 11a (element facing range 15a) is the non-target conductor (bus bar 13b, 13c). Leaning on. As described with reference to FIG. 1, the influence of the noise magnetic flux on the magnetron conversion element 11a can be suppressed by the inclination of the element facing ranges of the shield plates 14 and 15.

The magnetic-electric conversion element 11b measures the magnetic flux generated by the current flowing through the bus bar 13b (the magnetic flux generated by the bus bar 13b). The geometrical relationship between the bus bar 13a-13c of the magnetron conversion element 11b and the pair of shield plates (upper shield plate 14 and lower shield plate 15) is the same as that of the magnetron conversion element 11a. The target conductor of the magnetron conversion element 11b is the bus bar 13b. The magnetron conversion element 11b is adjacent to the bus bar 13b in the Z direction, and its magnetic sensing direction Sd faces the Y direction. For the magnetic-electric conversion element 11b, the bass bars 13a and 13c are non-target conductors, and the magnetic flux generated by them becomes a noise magnetic flux. Of the surfaces facing the bus bar, the range of the upper shield plate 14 facing the magnetron conversion element 11b (element facing range 14b) is inclined toward the non-target conductors (bus bar 13a, 13c). Similarly, of the surface of the lower shield plate 15 facing the bus bar, the range facing the magnetron conversion element 11b (element facing range 15b) is tilted toward the non-target conductors (bus bar 13a, 13c). There is. The influence of the noise magnetic flux on the magnetron conversion element 11b can be suppressed by the inclination of the element facing range of the pair of shield plates (upper shield plate 14, lower shield plate 15).

Hereinafter, a modified example of the current sensor will be described. In the cross-sectional views of FIGS. 6-9 and 11 below, the hatching showing the cross section of the resin mold 16 is omitted as in FIG. Further, in the following modification, the same parts as the parts of the current sensor 10 of the embodiment are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 6 shows a cross-sectional view of the current sensor 110 of the first modification. In the current sensor 110, of the pair of shield plates (upper shield plate 14, lower shield plate 115), the upper shield plate 14 is located closer to the magnetron conversion elements 11a and 11b than the lower shield plate 115. In the upper shield plate 14, the range of the lower surface facing the bus bar 13a-13c facing the magnetron conversion element 11a for measuring the current of the bus bar 13a (element facing range 14a) is a non-target conductor for the magnetron conversion element 11a. It is tilted in the direction of the bus bars 13b and 13c. Further, the range facing the magnetron conversion element 11b for measuring the current of the bus bar 13b (element facing range 14b) is inclined in the direction of the bus bars 13a and 13c which are non-target conductors for the magnetron conversion element 11b. This point is the same as that of the current sensor 10. In the current sensor 110, the upper surface 115a of the lower shield plate 115 farther from the magnetron conversion elements 11a and 11b facing the bus bar 13a-13c is perpendicular to the Z direction. In this way, if the element facing ranges 14a and 14b of the shield plates on the side closer to the magnetron conversion elements 11a and 11b of the pair of shield plates 14 and 115 are tilted toward the non-target conductor, the noise magnetic flux The impact can be expected to be reduced.

FIG. 7 shows a cross-sectional view of the current sensor 210 of the second modification. In the current sensor 210, the range of the pair of shield plates 214 and 215 facing the magnetron conversion elements 11a (element facing ranges 214a and 215a) is inclined toward the non-target conductors bus bars 13b and 13c. The range is not flat and is curved in a concave shape. As described above, the element facing ranges 214a and 215a may be curved as long as they are inclined toward the non-target conductor. In the element facing range 214a and 215a, the distance dH1 (dH2) between the plane Ha extending in the Y direction through the magnetron conversion element 11a and the element facing range 214a (215a) along the Z direction is a non-target conductor (bus bar 13b, 13c). ) Should be gradually increased. In the current sensor 210, the element facing surfaces 214b and 215b with respect to the magnetron conversion element 11b for measuring the current of the bus bar 13b are also inclined toward the non-target conductors (bus bar 13a, 13c), but are curved in a concave shape.

FIG. 8 shows a cross-sectional view of the current sensor 310 of the third modification. In the current sensor 310, the range of the pair of shield plates 314 and 315 facing the magnetron conversion elements 11a (element facing ranges 314a and 315a) is inclined toward the non-target conductors bus bars 13b and 13c. The range is not flat and is curved in a convex shape. Similarly, the range facing the magnetron conversion element 11b (element facing range 314b, 315b) is inclined toward the non-target conductors bus bars 13a and 13c, but these ranges are not flat and are curved in a convex shape. doing. In this way, the device facing range may be curved in a convex shape. The curved surface in the element facing range can be realized by processing with a milling cutter or the like.

FIG. 9 shows a cross-sectional view of the current sensor 410 of the fourth modification. In the current sensor 410, the pair of shield plates (upper shield plate 414, lower shield plate 415) are bent. Even in this current sensor 410, the element facing ranges 414a and 415a with respect to the magnetron conversion element 11a for measuring the current of the bus bar 13a are inclined toward the bus bars 13b and 13c which are non-target conductors. Further, the element facing ranges 414b and 415b with respect to the magnetron conversion element 11b for measuring the current of the bus bar 13b are inclined toward the bus bars 13a and 13c which are non-target conductors. In this way, the shield plates 414 and 415 may be bent to realize an element facing range that is inclined toward the asymmetric conductor.

FIG. 10 shows a perspective view of the current sensor 510 of the fifth modification, and FIG. 11 shows a cross-sectional view taken along the line XI-XI of FIG. In FIG. 10, the resin mold 16 is not shown. In the current sensor 510, the upper shield plate 514 is provided with slits 514c at three positions, and the bath bars 13a-13c are fitted into the slits, respectively. The lower shield plate 515 is also provided with slits 515c at three locations, and the bass bars 13a-13c are fitted into the slits. In FIG. 10, the two slits of the lower shield plate 515 are hidden and cannot be seen. As shown in FIG. 11, even in the current sensor 510, the element facing ranges 514a and 515a with respect to the magnetron conversion element 11a for measuring the current of the bus bar 13a are inclined toward the bus bars 13b and 13c which are non-target conductors. Further, the element facing ranges 514b and 515b with respect to the magnetron conversion element 11b for measuring the current of the bus bar 13b are inclined toward the bus bars 13a and 13c which are non-target conductors. The pair of shield plates 514 and 515 may sandwich at least a part of each of the bus bars 13a-13c, and as shown in FIGS. 10 and 11, another part of the bus bars 13a-13c is a pair of shield plates 514. It may be out of the range of 515. The distance between the shield plates 514 and 515 can be shortened by providing slits in the shield plates 514 and 515 and exposing a part of the bus bars 13a and 13c from the space between the pair of shield plates 514 and 515 to the outside. it can. As a result, the current sensor 510 can be miniaturized.

The points to be noted regarding the technique described in the examples will be described. For the magnetron conversion element 11a, the bus bar 13a is the target conductor for current measurement, and the bus bars 13b and 13c correspond to the non-target conductors. Focusing on the magnetron conversion element 11a, the bus bar 13a corresponds to the first conductor, and the bus bars 13b and 13c correspond to the second conductor. For the magnetron conversion element 11b, the bus bar 13b is the target conductor for current measurement, and the bus bars 13a and 13c are non-target conductors. Focusing on the magnetron conversion element 11b, the bus bar 13b corresponds to the first conductor, and the bus bars 13a and 13c correspond to the second conductor.

The X direction of the embodiment corresponds to the first direction of the claim, the Y direction corresponds to the second direction, and the Z direction corresponds to the third direction.

The current sensor of the embodiment has three bus bars and includes two magnetron conversion elements. The number of bus bars lined up may be any number as long as there are two or more. The current sensor may include at least one magnetron conversion element. In the current sensor disclosed in the present specification, the element facing range of the shield plate should be inclined toward the other bus bars with respect to the magnetron conversion element corresponding to the bus bars located at the ends of the arrangement of the plurality of bus bars. Just do it.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. The technical elements described herein or in the drawings exhibit their technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

2, 10, 102, 110, 210, 310, 410, 510: Current sensor 3, 103: Target conductor 4, 104: Non-target conductor 5, 11a, 11b, 105: Electromagnetic conversion elements 6, 14, 106, 114, 214, 314, 414, 514: Upper shield plate 6a: Element facing range 7, 15, 107, 115, 215, 315, 415, 515: Lower shield plate 12a, 12b: Notch 13a-13c: Bus bar 14a, 14b, 15a , 15b, 214a, 214b, 215a, 215b, 314a, 314b, 315a, 315b, 414a, 414b, 415a, 415b, 514a, 514b, 515a, 515b: Element facing range 514c, 515c: Slit 16: Resin mold 20: Power Converter 21: Voltage converter 22: Inverter 23: Motor 30: Housing 31a-31d: Semiconductor module 32: Cooler 37: Laminated unit 38: Capacitor unit 39: Leaf spring 52: Battery 53: Filter capacitor 54: Reactor 54a: Coil 56a-56h: Transistor 57: Smoothing capacitor 59: Controller

Claims (1)

The first conductor extending in the first direction and
A second conductor that extends parallel to the first conductor and is aligned with the first conductor in a second direction orthogonal to the first direction.
A magnetron conversion element that is adjacent to the first conductor in a third direction that is orthogonal to each of the first direction and the second direction and whose magnetic sensitivity direction is the second direction.
A pair of shield plates sandwiching the first conductor, the second conductor, and the magnetron conversion element in the third direction,
Is equipped with
At least the shield plate on the side close to the magnetron conversion element has a surface facing the first and second conductors, and the range facing the magnetron conversion element is inclined toward the second conductor. Sensor.