JP2020008419A - Power converter - Google Patents

Abstract

To realize reduction of the cost of a current sensor in a power converter.SOLUTION: In the power converter, a current sensor 250 includes: a magnetic core 21, penetrating an alternating-current conductor 11 and forming a gap 31 and a gap 32; a magnetic core 22, penetrating an alternating-current conductor 12 and forming a gap 33 and a gap 34; and a magnetic core 23, penetrating an alternating-current conductor 13 and forming a gap 35 and a gap 36. The current sensor 250 includes: a current detection element 41 in the gap 31; a current detection element 42 across the gap 32 and the gap 33; a current detection element 43 across the gap 34 and the gap 35; and a current detection element 44 in the gap 36. The current detection elements 41 to 44 detect a magnetic flux passing through the current detection elements in a vertical direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a power conversion device used to convert DC power into AC power or convert AC power into DC power.

  2. Description of the Related Art A power conversion device used for driving a motor of a vehicle is required to continuously operate even when a built-in component fails for high reliability. As a configuration that can continue operation even when a component fails, a method of making the function redundant is often used.

  The power converter detects an alternating current that is an output of the power converter in order to control the output current, and changes the timing of turning on and off the power semiconductor in the device to obtain a desired current value. Controlling the current. In a current sensor that detects an output current, there is a method in which one current to be detected is detected by using two current sensors to make it redundant, so that it can continue to operate even when one of the current sensors fails. General.

  As a method of detecting a current, as disclosed in Patent Document 1, a current through which a current to be detected flows through a magnetic core having a gap, and a magnetic field near the conductor is detected by a Hall element installed in the gap. Sensors are often used. To make such a current sensor redundant, the magnetic cores are doubled, and the magnetic field passing through each core is detected by a double Hall element.

  Patent Document 2 discloses a current sensor that detects a current without using a magnetic core. However, when such a current sensor is made redundant, the number of current detection elements such as a Hall element is doubled. Becomes

JP 2003-14789 A JP 2005-207791 A

  However, in the above-described related art, since the magnetic field passing through the one-phase magnetic core is detected by the two current detection elements, the number of current detection elements in the current detection target phase is doubled. As the number of current detecting elements increases, there is a problem that the cost of the current sensor increases.

  The present invention has been made in view of the above points, and has as its object to propose a power converter that can reduce the cost of the current sensor in the power converter.

  In order to solve such a problem, in the present invention, a power converter includes a first magnetic core penetrating a first AC conductor and forming a first gap, and a second magnetic core penetrating a second AC conductor and forming a first gap. And a first current detecting element disposed so as to straddle the first gap and the second gap.

  According to the present invention, cost reduction of a current sensor in a power converter can be realized.

FIG. 2 is a diagram illustrating a configuration example of a power converter according to the first embodiment. FIG. 1 is a perspective view schematically illustrating an example of the appearance of a power conversion device according to a first embodiment. FIG. 2 is a diagram illustrating a configuration example of a current sensor according to the first embodiment. 5 is a flowchart illustrating an example of a current detection element abnormality determination process according to the first embodiment. FIG. 9 is a diagram illustrating a configuration example of a current sensor according to a second embodiment. 9 is a flowchart illustrating an example of a current detection element abnormality determination process according to the second embodiment. FIG. 9 is a diagram illustrating a configuration example of a current sensor according to a third embodiment. FIG. 13 is a diagram illustrating a configuration example of a current sensor according to a modification of the third embodiment. FIG. 13 is a diagram illustrating a configuration example of a current sensor according to a fourth embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description of the embodiments, the same reference numerals are given to the same elements, and the description that follows will be omitted.

(1-1) Configuration Example of Power Conversion Device of First Embodiment FIG. 1 is a diagram illustrating a configuration example of a power conversion device of a first embodiment. The power converter 500 of this embodiment includes power semiconductor modules 100U, 100V, and 100W, a capacitor module 200, a positive conductor 310, and a negative conductor 320. Power conversion device 500 is a power conversion device that converts a DC current into a three-phase AC current or converts a three-phase AC current into a DC current.

  Each power semiconductor module is provided with an AC terminal. That is, power semiconductor module 100U has module AC terminal 150U. The power semiconductor module 100V has a module AC terminal 150V. The power semiconductor module 100W has a module AC terminal 150W. One ends of AC conductors 340U, 340V, and 340W are connected to module AC terminals 150U, 150V, and 150W, respectively, and the other ends (342U, 342V, and 342W) are connected to three-phase terminals of a motor (not shown), respectively. You. A current sensor 250 for detecting a current of each phase of UVW is provided on each of the AC conductors 340U, 340V, and 340W.

  The DC input / output positive terminal 319 of the positive conductor 310 is connected to the positive terminal of a high-voltage battery (not shown). The DC input / output negative terminal 329 of the negative conductor 320 is connected to the negative terminal of the high-voltage battery.

  Capacitor module 200 is electrically connected to positive electrode conductor 310 and negative electrode conductor 320.

  Each of the power semiconductor modules 100U, 100V, and 100W includes upper and lower arm semiconductor elements. In the following, an insulated gate bipolar transistor is used as an example of a semiconductor element, and is abbreviated as IGBT (Insulated Gate Bipolar Transistor). The power semiconductor is not limited to the IGBT but may be another power semiconductor such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

  For example, the V phase will be described as an example, but the U phase and the W phase are the same as the V phase. The upper arm of the power semiconductor module 100V includes an IGBT 161 and a diode 162. Further, a control terminal 171 for turning on / off the IGBT 161 is provided on the upper arm. The lower arm of the power semiconductor module 100V includes the IGBT 163 and the diode 164. The lower arm is provided with a control terminal 172 for turning on / off the IGBT 163.

  The collector of the IGBT 161 of the upper arm is provided with a module positive terminal 111 for connection to the positive conductor 310. The emitter of the lower arm IGBT 163 is provided with a module negative terminal 121 for connection to the negative conductor 320. A module AC terminal 150 V is provided between the emitter of the upper arm IGBT 161 and the collector of the lower arm IGBT 163.

  By switching control signals applied to the control terminal 171 of the upper arm and the control terminal 172 of the lower arm, the power converter 500 can convert a DC current into an AC current or an AC current into a DC current. For example, in a steady state in which the upper arm IGBT 161 of the power semiconductor module 100V is turned on and the lower arm IGBT 163 is turned off, a current flows from the positive conductor 310 to the module AC terminal 150V through the module positive terminal 111. Conversely, in a steady state in which the upper arm IGBT 161 of the power semiconductor module 100V is turned off and the lower arm IGBT 163 is turned on, current flows from the module AC terminal 150V toward the module negative terminal 121.

  The power conversion device 500 includes a control circuit board 50 having an inverter control unit 51 and a current calculation unit 52.

  The inverter control unit 51 is a processing device such as a microcomputer, which is an example of an ASIC (Application Specific Integrated Circuit). The inverter control unit 51 determines whether each of the power semiconductor modules 100U, 100V, and 100W is based on the motor torque command value and the motor output current (measured current value) calculated from the output voltage by the current calculation unit 52. A gate drive command is output to the arm and the lower arm.

  Further, the current calculation unit 52 determines an abnormality of the current sensor 250 based on the detection result of the output voltage of the current sensor 250, as described later. The current calculation unit 52 determines the abnormality of the current sensor 250 and, when identifying which of the current detection elements described later is abnormal, excludes without using the output voltage of the current detection element identified as abnormal, The output current of the motor is calculated using the output voltage of the current detection element that is not abnormal.

(1-2) External Appearance of Power Conversion Device of First Embodiment FIG. 2 is a perspective view schematically illustrating an external appearance example of the power conversion device of the first embodiment. The power converter 500 includes a positive conductor 310, a negative conductor 320, AC conductors 340U, 340V, and 340W, power semiconductor modules 100U, 100V, and 100W, a capacitor module 200, and a current sensor 250. You.

  The capacitor module 200 includes a positive terminal electrically connected to the positive conductor 310 and a negative terminal electrically connected to the negative conductor 320.

  Taking the W phase as an example, the module positive terminal 111 of the power semiconductor module 100W is electrically connected to the positive terminal 311 of the positive conductor 310. The module negative terminal 121 of the power semiconductor module 100W is electrically connected to the negative terminal 321 of the negative conductor 320. Module AC terminal 150W of power semiconductor module 100W is electrically connected to AC terminal 341 of AC conductor 340W. The current sensor 250 is installed such that the AC conductor 340W passes through the current sensor 250 and the AC terminal 342W is drawn out. In FIG. 2, the AC conductor 340W is a bus bar, but may be a column or a cable. The U phase and the V phase are the same as the W phase.

(1-3) Configuration Example of Current Sensor of First Embodiment Next, a configuration example of a redundant current sensor that can reduce the number of magnetic cores and current detection elements will be described. FIG. 3 is a diagram illustrating a configuration example of the current sensor according to the first embodiment. FIG. 3 is a cross-sectional view of the current sensor 250 shown in FIG. 1 in a cross section perpendicular to the longitudinal direction of the AC conductors 340U, 340V, and 340W. In the following, AC conductors 340U, 340V, and 340W are read as AC conductors 11, 12, and 13, but the correspondence between AC conductors 340U, 340V, and 340W and AC conductors 11, 12, and 13 is particularly limited. Not something.

  The current sensor 250 penetrates the AC conductor 11 and forms the gaps 31 and 32, the magnetic core 22 penetrates the AC conductor 12 and forms the gaps 33 and 34, and penetrates the AC conductor 13. And a magnetic core 23 forming a gap 35 and a gap 36.

  Further, the current sensor 250 includes the current detection element 41 in the gap 31, the current detection element 42 so as to bridge the gap 32 and the gap 33, the current sensor 250 includes the current detection element 43 so as to bridge the gap 34 and the gap 35, 36 has a current detection element 44. The current detecting elements 41 to 44 detect a magnetic flux passing through the current detecting elements in the vertical direction.

  The current detecting element 41 detects a magnetic flux Φ1 generated by the current I1 flowing through the AC conductor 11 and linked to the magnetic core 21. The current detecting element 42 detects the magnetic flux Φ1 and the magnetic flux Φ2 generated by the current I2 flowing through the AC conductor 12 and linked to the magnetic core 22. The current detecting element 43 detects the magnetic flux Φ2 and the magnetic flux Φ3 generated by the current I3 flowing through the AC conductor 13 and linked to the magnetic core 23. The current detecting element 44 detects the magnetic flux Φ3.

  Hall elements or the like are used as the current detection elements 41 to 44, and output a signal that changes according to the intensity of the magnetic fluxes Φ1, Φ2, and Φ3 penetrating the current detection elements.

  Here, assuming that output signals (output voltages) of the current detection elements 41, 42, 43, and 44 are V1, V2, V3, and V4, respectively, and a sensitivity coefficient to a magnetic flux passing through the current detection elements is F, the output signal V1 To V4 can be expressed by the following equations (1) to (4), respectively. In the following equations (1) to (4), the direction from the bottom to the top of the current detecting element in FIG. 3 is defined as the positive direction of the magnetic flux.

V1 = F · Φ1 (1)
V2 = F · (Φ2−Φ1) (2)
V3 = F · (Φ3-Φ2) (3)
V4 = −F · Φ3 (4)

  When the relationships between the magnetic fluxes Φ1, Φ2, and Φ3 and the output signals V1, V2, V3, and V4 are expressed by using the above formulas (1) to (4), they can be expressed by the following formulas (5) to (7). .

Φ1 = V1 / F =-(V2 + V3 + V4) / F (5)
Φ2 = (V1 + V2) / F = − (V3 + V4) / F (6)
Φ3 = (V1 + V2 + V3) / F = −V4 / F (7)

  From the above equations (5) to (7), based on the output signals V1, V2, V3, and V4 of the current detection elements 41, 42, 43, and 44, the currents I1, I2, And I3 can calculate the magnetic fluxes Φ1, Φ2, and Φ3. Further, the output signals V1, V2, V3, and V4 of the current detection elements 41, 42, 43, and 44 are calculated in advance by calculating the conversion coefficient from the magnetic flux intensity linked to the magnetic core to the current flowing through the AC conductor. Thus, it is possible to calculate the value of the current flowing through each of the AC conductors 11, 12, and 13.

(1-4) Example of Processing for Determining Abnormality of Current Detecting Element of First Embodiment As described above, magnetic fluxes Φ1, Φ2, and Φ3 generated by currents I1, I2, and I3 flowing through AC conductors 11, 12, and 13 are as described above. It can be calculated from Equations (5), (6) and (7). Further, from the above equations (5), (6), and (7), it can be seen that the magnetic fluxes Φ1, Φ2, and Φ3 can be represented by two types of mathematical expressions.

  For example, the magnetic flux Φ1 can be calculated based on the output signal V1 of the current detection element 41 from the above equation (5), and the output signal V2 of the current detection element, the output signal V3 of the current detection element, and the output signal of the current detection element. It can be calculated from two types of methods so that it can be calculated based on V4. That is, when the current detection element 41 is abnormal, the magnetic flux Φ1 can be calculated using the output signals V2, V3, and V4 of the current detection element 42, the current detection element 43, and the current detection element 44. .

  On the other hand, when any one of the current detection element 42, the current detection element 43, and the current detection element 44 is abnormal, the magnetic flux Φ1 can be calculated from the output signal V1 of the current detection element 41. Similarly, the magnetic flux Φ2 and the magnetic flux Φ3 can be calculated from the above formulas (6) and (7) by two types of mathematical expressions, and the magnetic flux Φ2 and the magnetic flux Φ3 are obtained by using the output signals of the current detecting elements excluding the abnormal current detecting element. It is possible to calculate Φ1, Φ2, and Φ3.

  Next, a method of determining an abnormal current detection element will be described. In the following, for simplicity, the description will be made under ideal conditions in which noise or the like is not superimposed on the output signal of the current detection element.

  When all the current detecting elements are normal, the following equation (8) is obtained from the above equations (1), (2), (3) and (4).

V1 + V2 + V3 + V4 = 0 (8)

  From the above equation (8), if the sum of the signal outputs V1, V2, V3, and V4 is zero, it can be determined that all current detection elements are normal. In other words, when the sum of V1, V2, V3, and V4 is not zero, it can be determined that one of the current detection elements is abnormal.

  Next, a case where one of the current detection elements is abnormal will be considered. Normally, the sum of the currents I1, I2, and I3 flowing through each AC conductor is zero, and the sum of the magnetic fluxes Φ1, Φ2, and Φ3 generated by these currents is also zero. That is, the following equation (9) is obtained.

Φ1 + Φ2 + Φ3 = 0 (9)

  The above equations (5), (6) and (7) are substituted into the above equation (9). First, the following equation (10) is obtained by modifying the above equation (9) without using the output signal V1 of the current detection element 41.

V2 + 2V3 + 3V4 = 0 (10)

  Similarly, when the above equation (9) is modified without using the output signals V2, V3, and V4, the following equations (11), (12), and (13) are obtained.

V1−V3−2V4 = 0 (11)
2V1 + V2-V4 = 0 (12)
3V1 + 2V2 + V3 = 0 (13)

  When the above equation (10) holds, it can be understood that the output signals V2, V3, and V4 are normal, and that V1 is abnormal. Similarly, when the above equation (11) holds, the output signals V1, V3, and V4 are normal, and it can be seen from this that V2 is abnormal. Similarly, when the above equation (12) is satisfied, it can be understood that the output signals V1, V2, and V4 are normal, and from this, V3 is abnormal. Similarly, when the above equation (13) is satisfied, it can be understood that the output signals V1, V2, and V3 are normal, and that V4 is abnormal. In this way, the current detecting element in which the abnormality has occurred can be specified.

(1-5) Flowchart of abnormality determination processing of current detection element according to the first embodiment FIG. 4 is a flowchart illustrating an example of abnormality determination processing of a current detection element according to the first embodiment. The abnormality determination processing of the current detection element shown in FIG. 4 is repeatedly executed by the current calculation unit 52 at a predetermined cycle.

  First, in step S601, the current calculation unit 52 determines whether the above equation (8) holds. Step S601: In the case of Yes, the current calculation unit 52 determines that there is no abnormality in all the current detection elements (Step S605). Step S601: If No, the current calculation unit 52 determines that there is an abnormality in the current detection element, and shifts the processing to step S602.

  In step S602, the current calculation unit 52 determines whether the above equation (10) holds. Step S602: If Yes, the current calculator 52 determines that the current detection element 41 is abnormal (step S606). Step S602: In the case of No, the current calculation unit 52 determines that there is an abnormality in the current detection elements other than the current detection element 41, and shifts the processing to step S603.

  In step S603, the current calculation unit 52 determines whether the above equation (11) holds. Step S603: In the case of Yes, the inverter control unit 51 determines that the current detection element 42 is abnormal (step S607). Step S603: In the case of No, the current calculation unit 52 determines that there is an abnormality in the current detection element 43 or the current detection element 44, and shifts the processing to step S604.

  In step S604, the current calculation unit 52 determines whether the above equation (12) holds. Step S604: If Yes, the current calculation unit 52 determines that the current detection element 43 is abnormal (step S608). Step S604: If No, the current calculation unit 52 determines that the current detection element 44 has an abnormality. When steps S605 to S609 end, the current calculation unit 52 ends the current detection element abnormality determination processing of the first embodiment.

  In the flowchart of FIG. 4, the abnormality detection of the current detection element is performed using the above equations (10) to (12). However, a combination of three different equations among the above equations (10) to (13) is used. However, it is possible to determine the abnormality of the current detection element.

  Although the above description has been made on an ideal condition in which noise and the like are not superimposed, actually, noise is superimposed on the output of the current detection element. Therefore, at the time of abnormality determination of the current detection element described with reference to FIG. 4, the left sides of the above-described equations (10), (11), (12), and (13) are equal to or smaller than the threshold value according to each equation. It is realistic to judge by whether or not. For example, in step S601, it may be determined whether or not V1 + V2 + V3 + V4 ≦ Vth (Vth is a predetermined threshold) is satisfied instead of the equation (8).

  In FIG. 3, when the magnetic cores 21, 22, and 23 are omitted, the size and cost of the current sensor 250 can be reduced.

  According to the first embodiment, the configuration is such that the two phases share one current detection element instead of the redundancy in which two three-phase current detection elements are provided for each of the three phases. , The current sensor can be made redundant without doubling the number, and the current sensor can be reduced in size and cost can be reduced. Further, it is possible to specify which of the failed current detection elements. The current sensor 250 is useful for a power converter that supplies driving power to electric motors used in not only railway vehicles but also hybrid vehicles, electric vehicles, and industrial equipment.

(1-6) Modification of First Embodiment As a form including a modification of the current sensor 250 of the first embodiment shown in FIG. 3, there is a configuration of the following current sensor.

(Configuration 1): A current sensor including the magnetic core 21 and the magnetic core 22, the gap 32 and the gap 33, and the current detecting element 42. According to the current sensor of (Configuration 1), two-phase current detection can be performed by one current detection element. When two-phase currents are detected and one phase is calculated, the number of current detection elements can be reduced to reduce the cost of the current sensor.

(Configuration 2): A current sensor further including the magnetic core 23, the gap 34 and the gap 35, and the current detection element 43 in the above (Configuration 1). According to the current sensors of (Configuration 1) and (Configuration 2), three-phase current detection is performed by two current detection elements, so that the number of current detection elements can be reduced and the cost of the current sensor can be reduced.

(Configuration 3): The current sensor according to (Configuration 2) further including the gap 31 and the current detection element 41. According to the current sensors of (Configuration 2) and (Configuration 3), two-phase current detection is performed by three current detection elements, and the current detection elements have a redundant configuration with respect to detection of current flowing through any of the AC conductors. Therefore, the reliability can be improved while reducing the cost of the current sensor.

(Configuration 4): The current sensor according to (Configuration 3), further including the gap 36 and the current detection element 44. According to the current sensors of (Configuration 3) and (Configuration 4), the three-phase current detection is performed by the four current detection elements, and the current detection elements have a redundant configuration for detecting the current flowing through any of the AC conductors. Therefore, the reliability can be improved while reducing the cost of the current sensor.

(2-1) Configuration of Current Sensor of Second Embodiment FIG. 5 is a diagram illustrating a configuration example of the current sensor of the second embodiment. The current sensor 250B of the second embodiment is different from the first embodiment in that the magnetic core 23 is omitted.

(2-2) Example of Processing for Determining Abnormality of Current Detecting Element in Second Embodiment In the second embodiment, the above equation (3) is replaced by the following equation (3-1). In the second embodiment, the above equation (4) is not used.

V1 = F · Φ1 (1)
V2 = F · (Φ2−Φ1) (2)
V3 = −F · Φ2 (3-1)

  In the second embodiment, the above equations (5) to (6) are replaced by the following equations (5-1) to (6-1), respectively. In the second embodiment, the above equation (7) is not used.

Φ1 = V1 / F =-(V2 + V3) / F (5-1)
Φ2 = (V1 + V2) / F = −V3 / F (6-1)

  In the second embodiment, the above equation (8) is replaced by the following equation (8-1).

V1 + V2 + V3 = 0 (8-1)

  In the second embodiment, the above equation (9) is replaced by the following equation (9-1).

Φ1 + Φ2 = 0 (9-1)

  In the second embodiment, the expressions (10) to (12) are replaced by the following expressions (10-1) to (12-1). In the second embodiment, the above equation (13) is not used.

V2 + 2V3 = 0 (10-1)
V1-V3 = 0 (11-1)
2V1 + V2 = 0 (12-1)

  When the above equation (10-1) is satisfied, it can be understood that the output signals V2 and V3 are normal, and this indicates that V1 is abnormal. Similarly, when the above equation (11-1) is satisfied, it can be understood that the output signals V1 and V3 are normal, and that the output signal V2 is abnormal. Similarly, when the above equation (12-1) is satisfied, it can be understood that the output signals V1 and V2 are normal, and from this, V3 is abnormal.

(2-3) Flowchart of Processing for Determining Abnormality of Current Detecting Element of First Embodiment FIG. 6 is a flowchart illustrating an example of processing for determining abnormality of a current detecting element of the second embodiment. The abnormality determination processing of the current detection element shown in FIG. 6 is repeatedly executed by the current calculation unit 52 at a predetermined cycle. In the abnormality determination processing of the current detection element according to the second embodiment illustrated in FIG. 6, steps S604 and S608 are deleted from the flowchart illustrated in FIG. 4, and step S601 is set to V4 = 0 instead of steps S601, S602, and S603. 1, S602-1, and S603-1 are adopted, and the process is shifted to step S608 in the case of step S603-1: No, which is different from the abnormality determination process of the current detection element of the first embodiment shown in FIG. .

  According to the second embodiment, the current is detected even in a configuration in which two-phase currents among the three phases are detected, and the remaining one-phase current is calculated by assuming that the three-phase currents are in a balanced state. The redundancy of the current detection elements provided in the two phases is ensured, and it is detected that any one of the current detection elements has failed, and the current is detected using the remaining two current detection elements in which no failure has occurred. Detection can be continued.

(3-1) Configuration Example of Current Sensor of Third Embodiment FIG. 7 is a diagram illustrating a configuration example of a current sensor of the third embodiment. In the first and second embodiments, the case where the shape of the magnetic core is circular has been described. The functions of the current sensors described in the first and second embodiments can be realized even if the core shape is appropriately changed as long as it is a magnetic core shape.

  Therefore, for example, as shown in FIG. 7, the magnetic core of the current sensor 250C is composed of magnetic cores 21C, 22C, and 23C whose cross sections perpendicular to the longitudinal direction of the AC conductors 11, 12, and 13 are square. There may be. The positional relationship between the AC conductors 11 to 13, the gaps 31 to 36, and the current detection elements 41 to 44 is the same as the current sensor 250 of the first embodiment shown in FIG. 3 except that the core shape is different. . Therefore, the current sensor 250C of the third embodiment can have a function similar to that of the current sensor 250 of the first embodiment, and can be reduced in size.

(3-2) Modified Example of Current Sensor of Third Embodiment In addition, for example, as in a current sensor 250C-1 of a modified example of the third embodiment whose configuration example is shown in FIG. 8, between the magnetic core 21C and the magnetic core 22C. Alternatively, shield members 251 and 252 for shielding magnetic flux may be provided between adjacent magnetic cores, such as between the magnetic cores 22C and 23C. The shield members 251 and 252 suppress the magnetic flux coupling between the magnetic flux Φ1 and the magnetic flux Φ2 and the magnetic flux coupling between the magnetic flux Φ2 and the magnetic flux Φ3 in the current sensor 250C-1. It is possible to prevent a decrease in the accuracy of abnormality detection in the abnormality determination processing of the used current detection element.

  In the first to third embodiments, the case has been described in which the AC conductors 11 to 13 and the current detection elements 41 to 44 are arranged substantially linearly. The functions of the current sensors described in the first to third embodiments can be realized by appropriately changing the arrangement of the AC conductors 11 to 13 and the current detection elements 41 to 44.

(4-1) Configuration Example of Current Sensor of Fourth Embodiment FIG. 9 is a diagram illustrating a configuration example of a current sensor of the fourth embodiment. For example, as shown in FIG. 9, the AC conductors 11, 12, and 13 may be arranged in a triangular shape in a cross section perpendicular to the longitudinal direction of the AC conductors 11, 12, and 13 to configure the current sensor 250D. As in the configuration examples of the current sensors of the first to third embodiments, the current sensor 250D includes a magnetic core 21D penetrating the AC conductor 11 and forming the gaps 31 and 32D, and a magnetic core 21D penetrating the AC conductor 12 and forming the gap. A magnetic core 22D that forms a gap 33D and a gap 34D, and a magnetic core 23D that penetrates the AC conductor 13 and forms a gap 35D and a gap 36 are provided.

  In addition, the current sensor 250D includes the current detection element 41 in the gap 31, the current detection element 42 over the gap 32D and the gap 33D, and the current sensor 43 over the gap 34D and the gap 35D. 36 has a current detection element 44.

  Even with such a configuration of the current sensor 250D, the current sensor can be downsized while having the same functions as those of the current sensors of the first to third embodiments.

  Note that the present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in an easy-to-understand manner, and the present invention is not necessarily limited to one having all the configurations described above. In the above-described embodiment, the Hall element is described as an example of the current detecting element. However, the same effect can be obtained when another current detecting element having the same function is used. Further, a part of the configuration of the embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. Further, for a part of the configuration of each embodiment, it is possible to add / delete / replace another configuration. In addition, each configuration and each process illustrated in the above-described embodiment and modified examples may be appropriately integrated, separated, or rearranged in the processing order according to the implementation mode and the processing efficiency. Further, for example, the above-described embodiments and modified examples may be partially or entirely combined within a range not inconsistent.

11, 12, 13: AC conductors 21, 21C, 21D, 22, 22C, 22D, 23, 23C, 23D: Magnetic cores 31, 32, 32D, 33, 33D, 34, 34D, 35, 35D, 36: Gap 41 , 42, 43, 44: current detection elements 250, 250B, 250C, 250C-1, 250D: current sensors 251 and 252: shield member 500: power conversion device

Claims (10)

In a power converter having a current sensor,
The current sensor is
A first magnetic core penetrating the first AC conductor and forming a first gap;
A second magnetic core penetrating the second AC conductor and forming a second gap;
And a first current detection element disposed so as to extend over the first gap and the second gap. The current sensor is
The second magnetic core penetrates the second AC conductor and forms a third gap;
A third magnetic core penetrating the third AC conductor and forming a fourth gap;
The power conversion device according to claim 1, further comprising: a second current detection element disposed so as to extend over the third gap and the fourth gap. The current sensor is
The first magnetic core penetrates the first AC conductor and forms a fifth gap;
The power converter according to claim 2, further comprising a third current detection element disposed in the fifth gap. The current sensor is
The third magnetic core penetrates the third AC conductor and forms a sixth gap;
The power conversion device according to claim 3, further comprising: a fourth current detection element disposed in the sixth gap. The power converter according to any one of claims 1 to 4, wherein the magnetic core has a rectangular shape in a cross section perpendicular to a longitudinal direction of the AC conductor. The power converter according to claim 5, wherein a shield member that shields a magnetic flux is provided between the adjacent magnetic cores. The said 1st magnetic core, the said 2nd magnetic core, and the said 3rd magnetic core were arrange | positioned so that it might become triangular in the cross section perpendicular | vertical to the longitudinal direction of the said AC conductor. The power converter according to any one of claims 2 to 4. The power conversion device according to any one of claims 1 to 7, further comprising: a current calculation unit configured to calculate a measured current value from an output voltage of the current detection element. The power conversion device according to claim 8, wherein the current calculation unit specifies a failed current detection element from an output voltage of the current detection element. The power conversion device according to claim 8, wherein the current calculation unit calculates the measured current value excluding an output voltage of the failed current detection element.

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