JP2017116419A - Current sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for improving measurement precision of a current sensor which measures a current flowing through a bypass while taking an influence of a magnetic field generated by nearby electronic components into consideration.SOLUTION: A current sensor disclosed in the present specification is arranged in a magnetic field that a reactor L generates. Then the current sensor comprises: a first magnetoelectric transducer 4c arranged having a magnetism sensing direction Dc4 aligned with a tangent direction (Y-axial direction) of a circle having its center at a cross-sectional center of a bus bar 2c; a second magnetoelectric transducer 5c arranged having a magnetism sensing direction Dc5 aligned with an extension direction (X-axial direction) of the bus bar 2c; and a controller which corrects a measured value of the first magnetoelectric transducer 4c based upon a measured value of the second magnetoelectric transducer 5c and relative position relation between the second magnetoelectric transducer 5c and reactor L, and calculates a current of the bus bar 2c from the measured value having been corrected.SELECTED DRAWING: Figure 6

Description

  The technology disclosed in this specification relates to a current sensor that measures a current flowing through a bus bar using a magnetoelectric conversion element.

  For example, Patent Document 1 discloses a current sensor that measures a current flowing through a bus bar using a magnetoelectric conversion element. Generally, a magnetoelectric conversion element measures a component along a specific direction of a magnetic flux line penetrating the magnetoelectric conversion element. That direction is called the magnetosensitive direction. Note that the strength of the magnetic field is often expressed by magnetic flux density. The output of the magnetoelectric conversion element is a magnetic sensitive direction component of the magnetic flux density.

  The magnetoelectric conversion element of the current sensor disclosed in Patent Document 1 is arranged on the side surface of the bus bar so that the magnetic sensing direction is orthogonal to the direction in which the bus bar to be measured extends. This magnetoelectric conversion element measures the strength (magnetic flux density) of the magnetic field generated due to the current flowing through the bus bar to be measured. Hereinafter, for convenience of explanation, measuring the strength (magnetic flux density) of the magnetic field is simply referred to as “measuring the magnetic field”. A magnetic field generated due to the current flowing through the bus bar to be measured is referred to as a target magnetic field.

  The magnetoelectric transducer can also measure a magnetic field (noise magnetic field) other than the target magnetic field. Patent Document 1 further discloses a technique for reducing the influence of a noise magnetic field generated due to a current flowing through a non-measurement target bus bar extending in parallel with the measurement target bus bar. The cross-sectional shape of the non-measurement target bus bar is elongated and the center in the longitudinal direction is constricted with respect to both ends in the longitudinal direction. This cross-sectional shape reduces the component in the magnetic sensing direction of the noise magnetic field (noise magnetic flux) and reduces the influence of the noise magnetic field on the magnetoelectric transducer. Thereby, the measurement accuracy of the current sensor is improved.

JP2015-132499A

  Current sensors can be employed in various electronic devices. An electronic device includes various electronic components in order to realize its function. Among electronic components, there are components that generate a magnetic field having a high magnetic flux density, such as a reactor. Therefore, the magnetoelectric conversion element used for the current sensor can be affected by a magnetic field (noise magnetic field) generated by a nearby electronic component. In particular, when the electronic device is downsized, the distance between the bus bar and the electronic component is reduced, and the magnetoelectric conversion element is easily affected by a noise magnetic field. The current sensor described in Patent Document 1 can reduce the influence of a noise magnetic field generated from a non-measurement target bus bar extending in parallel, but cannot reduce the influence of a noise magnetic field generated from an electronic component. The present specification provides a technique for improving the measurement accuracy of a current sensor in consideration of the influence of a magnetic field generated from a nearby electronic component in a current sensor that measures a current flowing through a bus bar.

  The current sensor disclosed in the present specification is a sensor that measures a current flowing through a bus bar, and is disposed in a magnetic field generated by a specific electronic component. The current sensor includes a first magnetoelectric conversion element arranged so that a magnetic sensitive direction coincides with a tangential direction of a circle centering on a cross-sectional center of the bus bar, and a magnetic sensitive direction coincides with an extending direction of the bus bar. The measured value of the first magnetoelectric conversion element based on the second magnetoelectric conversion element arranged, the measured value of the second magnetoelectric conversion element, and the relative positional relationship between the second magnetoelectric conversion element and the specific electronic component And a controller for calculating the bus bar current from the corrected measurement value.

  According to this configuration, since the second magnetoelectric conversion element is arranged so that the magnetic sensing direction coincides with the extending direction of the bus bar, the magnetic field generated due to the current flowing through the bus bar is not measured and specified. Measure the magnetic field generated from the electronic components. Then, the controller corrects the measurement value of the first magnetoelectric conversion element based on the measurement value of the second magnetoelectric conversion element and the relative positional relationship between the second magnetoelectric conversion element and the specific electronic component. Thereby, the current value of the current flowing through the bus bar can be calculated in consideration of the influence of the magnetic field generated from the electronic component, and the measurement accuracy of the current sensor can be improved. Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a block diagram of the electric power system of the hybrid vehicle provided with the current sensor of an Example. It is a top view of the power converter device mounted in the hybrid vehicle. It is a perspective view of a bus bar. It is a top view of the bus bar of 1st Example. It is sectional drawing in the VV line of FIG. It is a schematic diagram which shows the relative positional relationship of a magnetoelectric conversion element and a reactor module. It is a top view of the bus bar of 2nd Example.

(First embodiment)
The current sensor of the first embodiment will be described with reference to the drawings. The current sensor of the first embodiment is provided in the hybrid vehicle 100. FIG. 1 is a block diagram of a power system of hybrid vehicle 100.

  The hybrid vehicle 100 includes a three-phase AC traveling motor 73, an engine 72, a power distribution mechanism 74, a power conversion device 30, a system main relay 60, a main battery 80, a feedback controller 91, a current sensor. 10 is provided. The main battery 80 is connected to the power conversion device 30 via the system main relay 60. The power conversion device 30 includes a voltage converter circuit 32 that boosts the power of the main battery 80 and an inverter circuit 31 that converts the boosted DC power into three-phase AC power. The three-phase AC power after conversion is supplied to the motor 73 via the three bus bars 2a-2c connecting the inverter circuit 31 and the motor 73. The output torque of the motor 73 and the output torque of the engine 72 are combined or distributed by the power distribution mechanism 74 and transmitted to the axle 75. Further, the motor 73 functions as a generator that converts regenerative energy into AC power when the hybrid vehicle 100 is braked. In this case, inverter circuit 31 converts AC power supplied from motor 73 into DC power, and voltage converter circuit 32 steps down the converted DC power to a voltage suitable for charging main battery 80. That is, the voltage converter circuit 32 is a so-called bidirectional converter circuit.

  The voltage converter circuit 32 includes a series circuit of two transistors Ta, a reactor L having one end connected to the midpoint of the series circuit and the other end connected to the high voltage end of the main battery 80, and a main battery. 80 includes a filter capacitor C1 connected in parallel with 80. On the other hand, in the inverter circuit 31, three sets of series circuits of two transistors Tb are connected in parallel. The three midpoints of the three sets of series circuits are connected to the three bus bars 2a-2c, respectively. The three bus bars 2a-2c are connected to the U phase, V phase, and W phase of the motor 73, respectively. In FIG. 1, reference numerals for some transistors are omitted. Diodes are connected in antiparallel to the transistors Ta and Tb. Since the operations of the voltage converter circuit 32 and the inverter circuit 31 are well known, detailed description thereof will be omitted.

  Further, a smoothing capacitor C <b> 2 is connected in parallel with both the circuits 31 and 32 between the voltage converter circuit 32 and the inverter circuit 31. The smoothing capacitor C <b> 2 smoothes the input current to the inverter circuit 31 or the input current to the voltage converter circuit 32.

  Current sensor 10 measures the current flowing through bus bar 2a-2c. The current sensor 10 includes an element package 6a-6c disposed in each of the bus bars 2a-2c and a sensor controller 92. Each element package contains a magnetoelectric conversion element for measuring a magnetic field generated due to a current flowing through each bus bar. In the present embodiment, each element package contains two magnetoelectric conversion elements, which will be described in detail later. The sensor controller 92 calculates the current value of the current flowing through the bus bar 2a-2c from the measured value supplied from the element package 6a-6c. The current sensor 10 will be described in detail later.

  The feedback controller 91 performs current feedback control in order to drive the motor 73 with the required torque. The feedback controller 91 calculates a control amount of current feedback control using the current value calculated by the sensor controller 92, and supplies a PWM signal corresponding to the control amount to the transistors Ta and Tb of the power conversion device 30. .

  With reference to FIG. 2, the component structure in the housing | casing of the power converter device 30 is demonstrated. FIG. 2 is a plan view of the power conversion device 30. In FIG. 2, illustration of a cover that closes the housing 40 of the power conversion device 30 is omitted.

  The power conversion device 30 includes a laminated unit 50, a capacitor module 41, a reactor module 42, a terminal block 43, and a housing 40 that houses the components 50 and 41-43. The stacking unit 50 is a unit for cooling the power cards 51a-51d, and the four power cards 51a-51d and the five coolers 53 are alternately stacked one by one. In FIG. 2, one of the five coolers is denoted by a reference numeral, and the other coolers are omitted. 2 shows an XYZ coordinate system, and the Y-axis coincides with the direction in which the four power cards 51a to 51d and the five coolers 53 are stacked (hereinafter referred to as a stacking direction). .

  Each of the power cards 51 a to 51 c seals two transistors Tb that constitute a set of series circuits of the inverter circuit 31. The power card 51d seals two transistors Ta constituting a series circuit of a voltage converter circuit.

  The five coolers 53 are connected by connecting pipes 55a and 55b, and the flow path inside each cooler is in communication with the connecting pipes 55a and 55b. A supply pipe 54a and a discharge pipe 54b are connected to the cooler at one end in the stacking direction. The refrigerant supplied through the supply pipe 54a is distributed to the five coolers 53 through the connection pipe 55a. The refrigerant absorbs heat from adjacent power cards as it passes through each cooler. The refrigerant that has passed through each cooler is collected in the connecting pipe 55b and discharged from the discharge pipe 54b. Note that the refrigerant is a liquid, typically water.

  The stacked unit 50 is inserted between a leaf spring 45 supported by a support 46 provided on the bottom surface of the housing 40 and the side wall of the housing 40, and a load is applied in the stacking direction by the elastic force of the leaf spring 45. It has been added. Due to this load, each power card and each cooler come into close contact.

  The terminal block 43 is arranged side by side with the stacked unit 50 in the X-axis direction, and is fixed to the side wall of the housing 40. The terminal block 43 includes three bus bars 2a-2c and element packages 6a-6c extending in parallel with the X-axis direction. One end of the bus bar 2a is exposed to the outside of the housing 40, and a power cable extending from the motor 73 is connected to the one end. The other end of the bus bar 2a is connected to the output terminal 52a among the three terminals protruding from the upper surface (the surface facing the positive direction of the Z-axis) of the power card 51a. The output terminal 52a is connected to the midpoint of a series circuit of the inverter circuit 31 (see FIG. 1). Similarly, one end of each bus bar of the bus bars 2b and 2c is connected to a power cable extending from the motor 73, and the other end is connected to each of the output terminals 52b and 52c protruding from the upper surfaces of the power cards 51b and 51c. Has been. In FIG. 2, reference numerals are given to one output terminal among the three terminals of each power card, and reference numerals of the other terminals are omitted.

  The capacitor module 41 is a module including a filter capacitor C1 and a smoothing capacitor C2 (see FIG. 1). The capacitor module 41 is arranged side by side with the multilayer unit 50 on the opposite side of the terminal block 43 in the X-axis direction. The reactor module 42 is a module including the reactor L (see FIG. 1) of the voltage converter circuit 32. The reactor module 42 is arranged side by side with the stacked unit 50 in the Y-axis direction (that is, the stacking direction) with the leaf spring 45 and the column 46 interposed therebetween.

  The bus bar 47 connects the output terminal 52d of the three terminals protruding from the upper surface of the power card 51d and the reactor module 42. The output terminal 52d is connected to the midpoint of the series circuit of the transistor Ta (see FIG. 1). The power conversion device 30 also includes a bus bar that connects the capacitor module 41 and the power cards 51a-51d and a bus bar that connects the power cards 51a-51d to each other. It should be noted that the bus bars are not shown in FIG. The power conversion device 30 also includes a board for realizing the feedback controller 91 and the sensor controller 92, but the board is not shown in FIG.

  The bus bar and the element package will be described with reference to FIGS. FIG. 3 is a perspective view of the bus bar 2a-2c. FIG. 4 is a plan view of the bus bar 2a-2c. FIG. 5 is a cross-sectional view taken along line VV in FIG. As described above, the bus bars 2a-2c are provided in the terminal block 43, but the main body of the terminal block 43 is not shown in FIGS. In addition, illustration of the main body of the terminal block 43 is also omitted in FIG.

  The bus bars 2a-2c are manufactured by an elongated metal plate. The cross section of the bus bar 2a-2c is a rectangle elongated in the Z-axis direction. The bus bars 2a-2c are arranged in parallel so that the wide side faces thereof. Each of the bus bars 2a-2c is provided with a notch 3a-3c having the same shape penetrating in the Y-axis direction. The notch 3a is provided with an offset in the X-axis positive direction with respect to the notch 3b of the adjacent bus bar 2b, and when viewed from the arrangement direction of the bus bars 2a-2c (that is, the Y-axis direction), The notch 3a and the notch 3b do not overlap. The notch 3c is also provided by being offset in the X-axis positive direction with respect to the notch 3b of the adjacent bus bar 2b, and the notch 3c and the notch 3b do not overlap when viewed from the Y-axis direction. As shown in FIG. 4, the notches 3a to 3c are arranged so as to be three vertices of the triangle.

  Each of the element packages 6a-6c is disposed inside the notches 3a-3c. The element package 6a accommodates two magnetoelectric conversion elements 4a and 5a. In FIG. 3, the outline of the element package 6a is drawn with a broken line. Similarly, the element package 6b accommodates two magnetoelectric conversion elements 4b and 5b, and the element package 6c accommodates two magnetoelectric conversion elements 4c and 5c.

  When a current flows in the extending direction of the bus bar 2c (that is, the X-axis direction), a magnetic field is generated around the bus bar 2c due to the current. A magnetic flux density representing the strength of a magnetic field (target magnetic field) generated due to the current flowing through the bus bar 2c is referred to as a target magnetic flux density MB. As shown in FIG. 5, the target magnetic field (target magnetic flux density MB) is generated so as to surround the cross section of the bus bar 2c when viewed from the extending direction. In general, the magnetic flux density is proportional to the current density of the current flowing through the bus bar. Here, the location where the notch 3c of the bus bar 2c is provided has a smaller cross-sectional area and a higher current density than other locations. By increasing the current density, the magnetic flux density is also increased. By disposing the element package 6c inside the notch 3c, the magnetoelectric conversion element in the element package 6c measures the target magnetic flux density MB increased by the notch 3c. Similarly, the magnetoelectric transducers in the element packages 6a and 6b also measure the magnetic flux density increased by the notches 3a and 3b. As described above, the notches 3b of the adjacent bus bars 2b do not overlap the notches 3c of the bus bars 2c when viewed from the arrangement direction (see FIGS. 4 and 5). Thereby, it is possible to prevent the target magnetic field generated from the bus bar 2b whose magnetic flux density is increased by the notch 3b from affecting the element package 6c disposed inside the notch 3c of the bus bar 2c. Similarly, it is possible to prevent the magnetic field generated from the adjacent bus bar from affecting the magnetoelectric conversion elements in the element packages 6a and 6b.

  With reference to FIGS. 4 and 5, the magnetoelectric conversion element in the element package will be described. The element packages 6a-6c have the same configuration. Hereinafter, the element package 6c will be described as a representative. The element package 6c includes a first magnetoelectric transducer 4c for measuring the intensity of the target magnetic field (target magnetic flux density MB) generated due to the current flowing through the bus bar 2c, and a magnetic field (noise magnetic field) generated by the reactor L. Is provided with a second magnetoelectric transducer 5c for measuring the strength (noise magnetic flux density). The 1st magnetoelectric conversion element 4c and the 2nd magnetoelectric conversion element 5c are arrange | positioned so that it may adjoin within the notch 3c. In general, the magnetoelectric transducer detects only a magnetic flux in a specific direction. That direction is called the magnetosensitive direction. The arrow to which the code | symbol Dc4 is attached | subjected shows the magnetosensitive direction of the 1st magnetoelectric conversion element 4c. As shown in FIG. 4, the first magnetoelectric conversion element 4c is disposed in the notch 3c so that the magnetic sensing direction Dc4 is orthogonal to the extending direction of the bus bar 2c (ie, the X-axis direction). In other words, as shown in FIG. 5, the first magnetoelectric transducer 4c is arranged so that the magnetic sensing direction Dc4 coincides with the tangential direction of a circle centered on the cross-sectional center of the bus bar 2c. Here, as shown in FIGS. 4 and 5, the target magnetic field (target magnetic flux density MB) is generated in a direction that coincides with the tangential direction of the circle on a plane orthogonal to the extending direction. Therefore, the first magnetoelectric transducer 4c can measure the target magnetic field (target magnetic flux density MB).

  Moreover, the arrow attached | subjected code | symbol Dc5 shows the magnetosensitive direction of the 2nd magnetoelectric conversion element 5c. As shown in FIG. 4, the second magnetoelectric conversion element 5c is arranged such that the magnetic sensing direction Dc5 coincides with the extending direction of the bus bar 2c (that is, the X-axis direction). Here, the magnetosensitive direction Dc5 does not coincide with the direction in which the target magnetic field (target magnetic flux density MB) is generated. Therefore, the second magnetoelectric conversion element 5c does not measure the target magnetic field.

  Around the reactor module 42, a magnetic field (noise magnetic field) due to the current flowing through the reactor L is generated. The reactor L is an electronic component including a coil, and a noise magnetic field having a high magnetic flux density is generated from the coil. The terminal block 43 including the magnetoelectric conversion elements 4c and 5c is accommodated in the housing 40 together with the reactor module 42 (see FIG. 2). Therefore, the magnetoelectric conversion elements 4c and 5c are arranged in a noise magnetic field. Therefore, the first magnetoelectric transducer 4c measures not only the target magnetic field (magnetic flux density MB) but also the noise magnetic field (noise magnetic flux density). In the present embodiment, the sensor controller 92 corrects the measurement value of the first magnetoelectric conversion element using the measurement value of the second magnetoelectric conversion element in order to reduce the influence of the noise magnetic field.

  With reference to FIG. 6, a method of correcting the measurement value of the first magnetoelectric conversion element using the measurement value of the second magnetoelectric conversion element will be described. Below, the magnetoelectric conversion elements 4c and 5c of the bus bar 2c will be described as a representative. FIG. 6 is a schematic diagram showing a relative positional relationship between the magnetoelectric conversion elements 4 c and 5 c and the reactor module 42.

  The positional relationship between the second magnetoelectric conversion element 5 c and the reactor module 42 is uniquely determined by the layout of the terminal block 43 and the reactor module 42 in the housing 40. Therefore, the direction of the noise magnetic field (noise magnetic flux density ML) passing through the second magnetoelectric transducer 5c is uniquely determined. As described above, since the magnetic sensing direction Dc5 of the second magnetoelectric conversion element 5c coincides with the bus bar extending direction (that is, the X-axis direction), the second magnetoelectric conversion element 5c has a noise magnetic field (noise magnetic flux density ML). The component MLx, which is the X-axis component, is detected, and a measurement value indicating the magnetic flux density of the component MLx is output. Therefore, the ratio between the component MLx and the component MLy that is the Y-axis component of the noise magnetic field (noise magnetic flux density ML) is determined from the direction of the uniquely determined noise magnetic field (noise magnetic flux density ML), and the measured value indicating the magnetic flux density of the component MLx The magnetic flux density of the component MLy can be calculated. As described above, the second magnetoelectric transducer 5c does not measure the target magnetic field (target magnetic flux density MB). That is, the measurement value of the second magnetoelectric conversion element 5c does not depend on the current flowing through the bus bar 2c but depends on the magnetic field generated by the reactor L.

  On the other hand, the first magnetoelectric conversion element 4c detects not only the target magnetic field (target magnetic flux density MB) but also the Y-axis component MN of the noise magnetic field (noise magnetic flux density ML) that passes through the first magnetoelectric conversion element 4c. That is, the first magnetoelectric transducer 4c measures and outputs a magnetic flux density obtained by synthesizing the Y-axis component MN of the target magnetic field (target magnetic flux density MB) and the noise magnetic field (noise magnetic flux density ML). Here, since the positional relationship between the first magnetoelectric conversion element 4c and the second magnetoelectric conversion element 5c is also uniquely determined, the magnetic flux density of the Y-axis component MN is correlated with the magnetic flux density of the component MLy. In the present embodiment, the sensor controller 92 uses the measured value of the second magnetoelectric conversion element 5c to detect the magnetic direction of the first magnetoelectric conversion element 4c (ie, the noise magnetic field density (noise magnetic flux density ML) passing through the second magnetoelectric conversion element 5c). , Y axis direction) component MLy is calculated, a correction value is estimated from the magnetic flux density, and the measurement value of the first magnetoelectric transducer 4c is corrected using the correction value. The correction value corresponds to the Y-axis component MN of the noise magnetic field (noise magnetic flux density ML) estimated from the magnetic flux density of the component MLy based on the correlation between the magnetic flux density of the Y-axis component MN and the magnetic flux density of the component MLy. Value. Generally speaking, the sensor controller 92 passes through the second magnetoelectric conversion element 5c determined by the measured value of the second magnetoelectric conversion element 5c and the relative positional relationship between the second magnetoelectric conversion element 5c and the reactor module 42. The measured value of the first magnetoelectric conversion element 4c is corrected based on the direction of the noise magnetic field (noise magnetic flux density ML) and the relative positional relationship between the first magnetoelectric conversion element 4c and the second magnetoelectric conversion element 5c.

  Specifically, it is realized as follows. The sensor controller 92 stores a map showing the relationship between the measurement value of the second magnetoelectric conversion element 5c and the correction value for correcting the measurement value of the first magnetoelectric conversion element 4c. The sensor controller 92 A correction value is calculated from the measurement value of the second magnetoelectric conversion element 5c using the map, and the measurement value of the first magnetoelectric conversion element 4c is corrected. The map is generated at the time of designing the power conversion device 30 by simulation or experiment.

  The sensor controller 92 calculates the current value of the current flowing through the bus bar 2c from the measured value of the first magnetoelectric transducer 4c corrected using the above map. The sensor controller 92 also includes a map showing the relationship between the measurement value of the second magnetoelectric conversion element 5a and the correction value for correcting the measurement value of the first magnetoelectric conversion element 4a, and the second magnetoelectric conversion element 5b. A map showing the relationship between the measured value and the correction value for correcting the measured value of the first magnetoelectric transducer 4b is also stored. The sensor controller 92 also corrects the measurement values of the first magnetoelectric transducers 4a and 4b using these maps, and calculates the current value of the current flowing through the bus bars 2a and 2b from the corrected measurement values.

  Here, the 2nd magnetoelectric conversion element 5a-5c does not detect the object magnetic flux which generate | occur | produces from a bus bar, but measures a noise magnetic field. Therefore, the measured value of the second magnetoelectric transducer 5a-5c is correlated with the current value of the current flowing through the reactor L. The sensor controller 92 stores a map indicating the relationship between the measured value of the second magnetoelectric transducer 5a-5c and the current value of the current flowing through the reactor L, and the current of the current flowing through the reactor L using the map. A value is also calculated. This map is generated at the time of designing the power conversion device 30 by simulation or experiment. That is, the second magnetoelectric transducers 5a-5c and the sensor controller 92 also constitute a current sensor that measures the current flowing through the reactor L. Thereby, it is not necessary to separately provide the power converter 30 with a current sensor that measures the current flowing through the reactor L, which contributes to the reduction of the manufacturing cost of the power converter 30.

  The effect of the present embodiment will be described. According to the above configuration, the second magnetoelectric conversion element 5c is arranged so that the magnetic sensing direction Dc5 coincides with the extending direction of the bus bar 2c (that is, the X-axis direction). Without measuring the magnetic field (target magnetic flux density MB), the noise magnetic field (noise magnetic flux density ML) generated from the reactor module 42 is detected. The sensor controller 92 is generated based on the relative positional relationship between the reactor module 42 and the second magnetoelectric conversion element 5c and the relative positional relationship between the first magnetoelectric conversion element 4c and the second magnetoelectric conversion element 5c. The correction value is calculated from the measured value of the second magnetoelectric conversion element 5c using the map, and the measured value of the first magnetoelectric conversion element 4c is corrected by the correction value. Thereby, the current value of the current flowing through the bus bar 2c can be calculated in consideration of the influence of the noise magnetic field generated from the reactor module 42, and the measurement accuracy of the current sensor can be improved.

(Modification)
A modification of this embodiment will be described. The positional relationship between the first magnetoelectric conversion element 4c of the bus bar 2c and the second magnetoelectric conversion element 5b of the bus bar 2b and the positional relationship between the first magnetoelectric conversion element 4c and the second magnetoelectric conversion element 5a of the bus bar 2a are also uniquely determined. ing. Since the magnetosensitive directions Da5 and Db5 of the second magnetoelectric conversion elements 5a and 5b do not coincide with the direction of the target magnetic field (target magnetic flux density MB) of the bus bar 2c, the second magnetoelectric conversion elements 5a and 5b Do not measure density MB). Thereby, based on the same idea as the first embodiment (see FIG. 6), it is possible to correct the measured value of the first magnetoelectric conversion element 4c from the measured value of the second magnetoelectric conversion element 5a-5c. In this modification, the sensor controller 92 stores a map showing the relationship between the measured values of the second magnetoelectric conversion elements 5a-5c and the correction values for correcting the measured values of the first magnetoelectric conversion element 4c. The sensor controller 92 may correct the measured value of the first magnetoelectric transducer 4c with the correction value calculated using the map. The measured values of the first magnetoelectric transducers 4a and 4b are also corrected by a similar map. Thereby, the measurement accuracy of the current sensor can be improved as in the first embodiment.

(Second embodiment)
With reference to FIG. 7, the current sensor of 2nd Example is demonstrated. FIG. 7 is a plan view of the bus bar 2a-2c, similar to FIG. In the present embodiment, the configuration of the element package is different from that of the first embodiment, and other configurations are the same as those of the first embodiment. Hereinafter, an element package having a configuration different from that of the first embodiment will be described.

  In the present embodiment, the second magnetoelectric conversion element is disposed only on the bus bar 2c and is not disposed on the bus bars 2a and 2b. That is, in this embodiment, the current sensor does not include the second magnetoelectric conversion elements 5a and 5b, but includes only the second magnetoelectric conversion element 5c. As in the first embodiment, the sensor controller 92 stores a map indicating the relationship between the measurement value of the second magnetoelectric conversion element 5c and the correction value for correcting the measurement value of the first magnetoelectric conversion element 4c. Yes. In the present embodiment, the sensor controller 92 further includes a map showing the relationship between the measurement value of the second magnetoelectric conversion element 5c and the correction value for correcting the measurement value of the first magnetoelectric conversion element 4a of the bus bar 2a, A map indicating the relationship between the measurement value of the second magnetoelectric conversion element 5c and the correction value for correcting the measurement value of the first magnetoelectric conversion element 4b of the bus bar 2b is stored. These maps are generated at the time of designing the power conversion device 30 by simulation or experiment based on the concept described in the first embodiment (see FIG. 6). The sensor controller 92 uses these maps to calculate the correction values of the first magnetoelectric conversion elements 4a-4c from the measurement values of the second magnetoelectric conversion elements 5c. Also in this embodiment, the measurement accuracy of the current sensor can be improved as in the first embodiment.

  Hereinafter, points to be noted regarding the technology shown in the embodiments will be described. The reactor module 42 is an example of the “specific electronic component” in the claims. In the technology disclosed in this specification, the first magnetoelectric transducer disposed adjacent to the current measurement target bus bar is placed in a magnetic field (noise magnetic field) generated by a component (specific electronic component) other than the bus bar. And reduce the influence of the noise magnetic field. The “specific electronic component” in the claims is not limited to the reactor of the embodiment, and may be, for example, a transformer, a coil, a resistor, or the like as long as it is a component that forms a strong magnetic field in the space including the first magnetoelectric conversion element. May be.

  In the above embodiment, the sensor controller 92 is an example of the “controller” in the claims, and the sensor controller 92 stores a map indicating the relationship between the measured value and the correction value of the second magnetoelectric transducer 5c. Yes. The sensor controller 92 may be mounted in the element package 6c.

  The 2nd magnetoelectric conversion element 5c does not need to be arrange | positioned at the bus bar 2c. For example, you may arrange | position in the terminal block 43 in the position away from the bus bar 2c, and may be arrange | positioned at the bus bar 47 which connects the reactor module 42 and the power card 51d.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit 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 technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2a-2c: bus bar 3a-3c: notch 4a-4c: first magnetoelectric conversion element 5a-5c: second magnetoelectric conversion element 6a-6c: element package 30: power conversion device 31: inverter circuit 32: voltage converter circuit 40 : Housing 41: Capacitor module 42: Reactor module 43: Terminal block 45: Leaf spring 50: Laminated unit 51a-51d: Power card 52a-52d: Output terminal 90: Controller 91: Feedback controller 92: Sensor controller 100: Hybrid vehicle C1: Filter capacitor C2: Smoothing capacitor L: Reactor Da4-Dc4, Da5-Dc5: Magnetosensitive direction MB: Target magnetic flux density ML: Noise magnetic flux density

Claims (1)

It is a current sensor that measures the current flowing through the bus bar and is arranged in a magnetic field generated by a specific electronic component,
A first magnetoelectric conversion element arranged such that a magnetic sensitive direction coincides with a tangential direction of a circle centering on a cross-sectional center of the bus bar;
A second magnetoelectric conversion element arranged such that a magnetic sensitive direction coincides with an extending direction of the bus bar;
Based on the measurement value of the second magnetoelectric conversion element and the relative positional relationship between the second magnetoelectric conversion element and the specific electronic component, the measurement value of the first magnetoelectric conversion element is corrected, A controller for calculating the current of the bus bar from the measured value;
A current sensor comprising:

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