JP7167804B2 - power converter - Google Patents

Description

The present disclosure relates to a power conversion device with current sensors.

Japanese Unexamined Patent Application Publication No. 2002-200000 discloses a current sensor used to detect a large current flowing through a motor or the like as a drive source for an electric vehicle. The current sensor of Patent Literature 1 includes a bus bar through which current to be detected flows, and a detection unit including a magnetic detection element. An intermediate portion of the busbar branches into a high resistance current path and a low resistance current path. A current to be detected is divided into a high-resistance current path and a low-resistance current path at a current division ratio corresponding to the resistance ratio of each current path.

The detection unit is attached to the high-resistance current path of the busbar and detects a magnetic field generated with an intensity proportional to the magnitude of the current flowing through the high-resistance current path. The current sensor estimates the current before shunting based on the current flowing through the high-resistance current path estimated based on the detected magnetic field intensity and the current shunting ratio. The current sensor can detect a current in a detection range wider than the detection range of the detection unit by detecting a part of the current to be detected and estimating the current before the shunting.

Japanese Patent Application Laid-Open No. 2010-38750

However, the shunt ratio may have an abnormality that deviates from the design value due to deformation of the bus bar or the like. Such an anomaly in the shunt ratio cannot be detected by the current sensor of Patent Document 1. Therefore, in the current sensor of Patent Document 1, when an abnormality occurs in the current division ratio, the current before the current division continues to be estimated with deviation from the actual current. Therefore, when the current sensor of Patent Document 1 is used to detect the current to be controlled and feedback control is performed in the power converter, an abnormality in the shunt ratio cannot be detected, and the accuracy of the current to be controlled decreases when an abnormality in the shunt ratio occurs. could arise.

An object of the present disclosure is to provide a power conversion device capable of detecting an abnormality in the shunt ratio and suppressing a decrease in accuracy of a current to be controlled.

The above objects are achieved by the combination of features stated in the independent claims, while the subclaims define further advantageous embodiments of the disclosure. The symbols in parentheses described in the claims indicate the corresponding relationship with specific means described in the embodiments described later as one aspect, and do not limit the technical scope of the present disclosure. .

The power conversion device of the present disclosure for achieving the above object is a member through which a controlled current flows, which has a branch section (54) branched into a plurality of branch current paths (55), and a predetermined controlled current At least one branch conductive member (51) is provided for each of the branch current paths to divide the current into each branch current path at a current division ratio of a plurality of detection units (57) for detection, a calculation unit (61) for calculating a branch current value flowing in each branch current path based on the detection value of each detection unit, and a branch current value of the plurality of branch current paths. A monitoring unit (62) monitors abnormality of the branch current values by comparison, and a control unit (63) controls the current to be controlled based on the value of the current to be controlled calculated by summing the branch current values. ), and three branch conductive members are provided corresponding to each phase of the three-phase alternating current, and the monitoring unit further detects when an abnormality in the branch current value occurs in any of the branch conductive members. If the sum of the three phases of the current to be controlled is zero, it is determined that there is an abnormality in the shunt ratio. judge .

According to the above configuration, the monitoring unit monitors each branch current value by comparing the branch current values with each other. Therefore, in the power converter, when an abnormality occurs in the detection section or in the division ratio, the monitoring section can detect that fact. Further, the control unit controls the current to be controlled based on the sum of the branch current values. The total branch current value takes the same value regardless of whether there is an abnormality in the shunt ratio, and fluctuates according to the magnitude of the current to be controlled that actually flows. Therefore, even when an abnormality occurs in the split ratio, the control unit can perform control based on the same value as when no abnormality occurs. Therefore, the power converter can detect an abnormality in the shunt ratio and suppress a decrease in accuracy of the current to be controlled.

It is a figure which shows the circuit structure of a power converter device. It is a figure which shows the connection relationship of a sensor unit. It is a figure which shows the structure of a sensor unit. It is a figure which shows the structure of the sensor unit of 2nd embodiment.

A plurality of embodiments of the present disclosure will be described below based on the drawings. In addition, in description of each embodiment, the code|symbol of the same number may be attached|subjected to the corresponding component, and the overlapping description may be abbreviate|omitted. When only part of the configuration is described, the previously described embodiments can be applied to other portions of the configuration. In addition, it is possible to combine not only the configurations explicitly specified in the description of each embodiment, but also the configurations partially even if they are not explicitly specified as long as there is no problem with the combination.

<First embodiment>
A power converter 1 of the first embodiment will be described with reference to FIGS. 1 to 3. FIG. First, the circuit configuration of the power converter 1 will be described with reference to FIG. The power conversion device 1 is a device that performs power conversion between a DC power supply 2 mounted on a vehicle and a motor generator 3 . The DC power supply 2 is a power supply unit that outputs a DC voltage and includes a rechargeable secondary battery such as a lithium ion battery. The motor generator 3 is, for example, a three-phase AC rotary electric machine that functions as a vehicle drive source during power running and as a generator during regeneration.

The power converter 1 drives the motor generator 3 by converting the DC voltage supplied from the DC power supply 2 into a three-phase alternating current and providing the same to the motor generator 3 during power running. In addition, the power conversion device 1 converts the power generated by the motor generator 3 into a DC voltage during regeneration so that the power can be used for charging the DC power supply 2 . The power converter 1 includes a filter capacitor 10 , a converter 20 , a smoothing capacitor 30 , an inverter 40 , a sensor unit 50 and a control circuit section 60 .

Filter capacitor 10 is a capacitor provided between positive electrode line 4P connected to the positive electrode of DC power supply 2 and negative electrode line 4N connected to the negative electrode. Filter capacitor 10 functions as a filter that removes noise from the DC voltage supplied from DC power supply 2 to converter 20 .

The converter 20 is a conversion circuit unit that converts a DC voltage into DC voltages of different values, including semiconductor switching elements, reactors, and the like. As the semiconductor switching element, for example, a reverse conducting insulated gate bipolar transistor or the like can be used. Converter 20 boosts a DC voltage provided from DC power supply 2 as a voltage between positive line 4P and negative line 4N. Converter 20 has a function of providing the boosted voltage to inverter 40 as a voltage between high potential line 5H and low potential line 5L. In addition, converter 20 has a function of stepping down a DC voltage obtained by rectifying a three-phase AC generated by regeneration of motor generator 3 by inverter 40 and providing it to DC power supply 2 .

The smoothing capacitor 30 is a capacitor provided between the high potential line 5H and the low potential line 5L. Smoothing capacitor 30 has a function of smoothing the boosted voltage between high potential line 5H and low potential line 5L provided from converter 20 to inverter 40 .

The inverter 40 is a conversion circuit unit that converts between a DC voltage and a three-phase AC voltage, including a plurality of semiconductor switching elements. Inverter 40 converts the DC voltage provided from converter 20 into a three-phase AC voltage and outputs it to U-phase output line 6U, V-phase output line 6V, and W-phase output line 6W. The inverter 40 has three upper and lower arms 41 that correspond one-to-one to the three output phases. Each upper and lower arm 41 is arranged in parallel to connect the high potential line 5H and the low potential line 5L. Each upper and lower arm 41 includes two semiconductor switching elements connected in series between the high potential line 5H and the low potential line 5L. A connection point between the two semiconductor switching elements of each upper and lower arm 41 is connected to the output line of the corresponding phase.

Inverter 40 controls the voltage and frequency of the output three-phase alternating current by individually controlling on/off switching of each switching element by control circuit section 60 . As a result, the three-phase alternating current supplied from the power converter 1 to the motor generator 3 is controlled. Therefore, each of the currents flowing through the U-phase output line 6U, the V-phase output line 6V, and the W-phase output line 6W corresponds to the “current to be controlled” in the power converter 1 .

The sensor unit 50 is a device for detecting controlled currents in the power converter 1 that flow through the U-phase output line 6U, the V-phase output line 6V, and the W-phase output line 6W. The sensor unit 50 of this embodiment includes a branch conductive member 51, a non-detection conductive member 56, and a detection section 57, as shown in FIGS.

The branch conductive member 51 is a conductive member that is made of a conductive material such as copper and that extends in a strip shape as a whole and passes a controlled current. The branch conductive member 51 and the non-detection conductive member 56, which will be described later, are also referred to as busbars. The sensor unit 50 of this embodiment is provided with two branch conductive members 51 individually corresponding to two phases of the three-phase alternating current. Specifically, a branch conductive member 51 corresponding to a portion of the U-phase output line 6U and a branch conductive member 51 corresponding to a portion of the V-phase output line 6V are provided. Each branch conductive member 51 has a motor-side connection portion 52 , an inverter-side connection portion 53 and a branch section 54 .

The motor-side connection portion 52 is a portion for connecting to a corresponding phase of the motor generator 3 . At least a portion of the motor-side connection portion 52 is exposed to the outside of the housing of the sensor unit 50 . A connector pulled out from the motor generator 3 is connected to the exposed portion of the motor-side connection portion 52 by fastening with a bolt or the like.

The inverter-side connecting portion 53 is a portion connected to the corresponding upper and lower arms 41 of the inverter 40 . At least a portion of the inverter-side connection portion 53 is exposed to the outside of the housing of the sensor unit 50 . A terminal extending from a semiconductor device in which a semiconductor switching element corresponding to the upper and lower arms 41 is packaged is connected to the exposed portion of the inverter-side connection portion 53 by welding or the like.

The branch section 54 is a section of the branch conductive member 51 branched into a plurality of branch current paths 55 located between the motor-side connection portion 52 and the inverter-side connection portion 53 . The branch section 54 of this embodiment has a rectangular plate shape divided into two branch current paths 55 by forming a slit extending along the extension direction at the center in the width direction. The width dimension and thickness dimension of each branch section 54 are substantially equal to the width dimension and thickness dimension of the non-detection conductive member 56 described later. Thus, the resistance per length of each branch segment 54 is substantially equal to the resistance per length of the non-sensing conductive member 56 .

The branch section 54 has a line-symmetrical shape with respect to the center line extending in the extending direction. At least a portion of the root side of the motor-side connection portion 52 and the inverter-side connection portion 53 extending from the branch section 54 has a line-symmetrical shape with respect to the center line of the branch section 54 .

Each branch current path 55 formed in the branch section 54 connects between the motor-side connection portion 52 and the inverter-side connection portion 53 in a parallel relationship. Accordingly, in the branch section 54 , the current to be controlled flowing between the motor-side connection portion 52 and the inverter-side connection portion 53 is split at a predetermined split ratio and flows through each branch current path 55 . The branch section 54 of the present embodiment is designed to divide the two branch current paths 55 into substantially equal sizes due to the axisymmetric shape described above. That is, each branch current path 55 carries half the current to be controlled. Therefore, the amount of heat generated per length in each branch current path 55 is reduced to about a quarter of the amount of heat generated per length of the non-detected conductive member 56 for the same control target current.

The non-detection conductive member 56 is a conductive member that is made of the same conductive material as the branch conductive member 51 and that extends in a strip shape as a whole and passes a controlled current. The sensor unit 50 of the present embodiment is provided with a non-detection conductive member 56 corresponding to the remaining one phase of the three-phase alternating current that is not supported by the two branch conductive members 51 . Specifically, a non-detection conductive member 56 that functions as part of the W-phase output line 6W is provided. Non-detection conductive member 56 is formed in a strip-like shape extending from one end on the side connected to motor generator 3 toward one end on the side connected to inverter 40 . The non-detection conductive member 56 is not provided with the corresponding detection portion 57 . Therefore, the current in W-phase output line 6W flowing between motor generator 3 and inverter 40 through non-detection conductive member 56 is not directly detected by detector 57 . The non-detection conductive member 56 is positioned at the end of the three bus bars in the arrangement direction of the three bus bars corresponding to the three phases.

The detection unit 57 is a current sensor device that enables calculation of the magnitude of the flowing current by detecting the strength of the magnetic field generated by the current. The detection unit 57 is a semiconductor package that detects a magnetic field at its own position, including a semiconductor chip on which a magnetic sensor such as a magnetoresistive effect element is formed. The detection unit 57 sequentially detects the strength and direction of the magnetic field along the detection axis in a predetermined direction, and outputs an electric signal indicating the detected value to the control circuit unit 60 . One detector 57 is provided for each branch current path 55 . That is, in the present embodiment, four detectors 57 are provided in one-to-one correspondence with the four branched current paths 55 in total of the two branched conductive members 51 .

Each detection unit 57 is mounted on, for example, one circuit board at predetermined intervals, and is fixed so as to have a predetermined positional relationship with respect to the branch conductive member 51, the magnetic shield, and the like. Each detection unit 57 is arranged at a position facing one surface of the corresponding branch current path 55 in such a posture that the detection axis is perpendicular to the extension direction of the branch current path 55 . Each detection unit 57 individually detects the intensity and direction of the magnetic field generated around the branch current path 55 according to the amount and direction of the current flowing through the corresponding branch current path 55 . Although the detection unit 57 is configured as a coreless sensor that does not use a magnetic core in this embodiment, it may be configured as a core type sensor that uses a magnetic core.

The control circuit unit 60 is, for example, an electronic control device that includes a memory as a non-transitional and substantial storage medium in which software is recorded non-temporarily, and a processor that executes the software recorded in the memory. The control circuit unit 60 performs various functions for controlling the operation of the power converter 1 by executing software. The functions exhibited by the control circuit unit 60 are configured to exhibit functions as a calculation unit 61 , a monitoring unit 62 , and a control unit 63 . A part or all of the functions exhibited by the control circuit section 60 may be provided by a processor realized in hardware by one or a plurality of ICs or the like.

The calculator 61 has a function of sequentially calculating branch current values flowing through the respective branch current paths 55 based on detection values sequentially output from the detectors 57 . The calculation unit 61 converts the detected values indicating the strength and direction of the magnetic field into branch current values indicating the amount and direction of the current according to a preset correspondence relationship. The correspondence relationship between the detected value and the branch current value is set, for example, according to the designed positional relationship of the detection unit 57 with respect to the branch current path 55 . The calculation unit 61 calculates the branch current value, for example, assuming that the direction of flow from the inverter 40 to the motor generator 3 is positive, and the reverse is negative. However, the corresponding relationship between positive/negative and direction may be reversed.

The monitoring unit 62 has a function of monitoring abnormal branch current values by comparing the branch current values of the plurality of branch current paths 55 with each other. The branch current value of this embodiment is designed to be half the value of the current flowing through the branch conductive member 51 . The monitoring unit 62 detects a state in which it is assumed that the branch current value deviates from such a design value as an abnormality in the branch current value.

Abnormalities in the branch current value include an abnormality in the detection unit 57 and an abnormality in the branch current ratio. An abnormality in the detection unit 57 is a state in which the correspondence relationship between the current actually flowing through the branch current path 55 and the detection value input to the control circuit unit 60 is different from the designed correspondence relationship. Abnormality of the detection unit 57 is caused by, for example, a change in the positional relationship of the detection unit 57 with respect to the branch current path 55, an abnormality of the magnetic sensor of the detection unit 57, a signal line, or the like. Abnormality of the current division ratio is a state in which the current division ratio of the current actually divided into each branch current path 55 differs from the designed current division ratio. Abnormalities in the branch current ratio are caused by, for example, variations in manufacturing of the branch conductive member 51, deformation, and the like.

The monitoring unit 62 of the present embodiment does not distinguish between an abnormality in the detection unit 57 and an abnormality in the branch ratio, and collectively detects them as an abnormality in the branch current value. The monitoring unit 62 determines whether the ratio of the branch current values of the two branch current paths 55 belonging to the same branch section 54 matches the design division ratio. That is, the monitoring unit 62 determines whether or not the branch current values of the two branch current paths 55 belonging to the same branch section 54 substantially match each other.

Whether or not they substantially match may be determined based on, for example, whether or not the difference between the absolute values is within about several percent of either one of the absolute values. The determination by the monitoring unit 62 may be performed, for example, each time the calculation unit 61 calculates the branch current value for each branch current path 55 once. Further, the determination by the monitoring unit 62 may be performed on the basis of the number of times the branch current values substantially match during each predetermined number of calculations of the branch current values and the comparison of the integrated value of each branch current value during the period.

The monitoring unit 62 sequentially determines whether or not there is an abnormality in the branch current values of the branch current paths 55 belonging to the two branch conductive members 51 corresponding to the U-phase output line 6U and the V-phase output line 6V. . When the monitoring unit 62 of the present embodiment determines that an abnormality has occurred in the branch current value of any of the output lines, it notifies the host ECU of the vehicle of the abnormality and notifies the user of the abnormality. have it implemented.

The control unit 63 has a function of controlling the magnitude and direction of the current to be controlled by individually controlling the ON/OFF of each semiconductor switching element of the inverter 40 . That is, the control unit 63 can be said to have a function of controlling the output torque of the motor generator 3 by controlling the energized state of the motor generator 3 . The control unit 63 sets the semiconductor switching elements to be turned on and their on-duty ratios for each of the upper and lower arms 41 based on, for example, an output torque request from a host ECU of the vehicle and detection signals from various sensors.

The control unit 63 performs control based on the value of the controlled current flowing through each branch conductive member 51 calculated by summing the branch current values for each branch conductive member 51 . The control unit 63 sets, for example, a target current value variation pattern for each phase for realizing a target output torque. The control unit 63 performs feedback control so as to vary the actual value of the current to be controlled in each phase detected using the detection unit 57 along the target current value.

The control unit 63 determines the actual value of the controlled current flowing through the non-detected conductive member 56 among the three phases based on the actual values of the controlled current in the two branch conductive members 51 . That is, the output from the inverter 40 to the motor generator 3 is a three-phase alternating current, and the total value of the three-phase currents to be controlled is zero. Therefore, the actual value of the controlled current flowing through the non-detected conductive member 56 is calculated by reversing the sign of the total value of the controlled currents in the two branch conductive members 51 . The control unit 63 controls the current to be controlled flowing through the non-detection conductive member 56 based on the value thus calculated.

[Summary of the first embodiment]
According to the first embodiment described above, the monitoring unit 62 monitors each branch current value by comparing the branch current values with each other. Therefore, in the power conversion device 1, when an abnormality occurs in the detection unit 57 or an abnormality in the shunt ratio, the monitoring unit 62 can detect that fact. Further, the control unit 63 controls the current to be controlled based on the sum of the branch current values. The total branch current value takes the same value regardless of whether there is an abnormality in the shunt ratio, and fluctuates according to the magnitude of the current to be controlled that actually flows. Therefore, the control unit 63 can perform control based on the same value as when no abnormality occurs even when an abnormality occurs in the division ratio. Therefore, the power conversion device 1 can detect an abnormality in the shunt ratio and suppress a decrease in accuracy of the current to be controlled.

Further, in this embodiment, the control unit 63 can control the current flowing through the non-detection conductive member 56 where the detection unit 57 is not provided, based on the controlled current flowing through the two branch conductive members 51 . Therefore, the power conversion device 1 can reduce the number of the detection units 57 for one phase corresponding to the non-detection conductive member 56 as compared with the case where the detection units 57 are provided for all three phases. Therefore, the power conversion device 1 can suppress an increase in the number of the detection units 57 for the purpose of mutual comparison by the monitoring unit 62 and allow the control unit 63 to perform control.

In addition, in the present embodiment, each branch conductive member 51 divides the current to be controlled substantially equally to each branch current path 55 . Contrary to the configuration of this embodiment, when an uneven configuration is adopted, the detection unit 57 of the branch current path 55 with a large shunted current has a wider detection range than the detection unit 57 of the branch current path 55 with a small current. and so on. Therefore, in the case of an uneven configuration, some detectors 57 have wider detection ranges than other detectors 57 or some detectors 57 have wider detection ranges than other detectors 57 do not use. With respect to the above-mentioned concern, in the configuration for dividing the current evenly, it is possible to configure each detection unit 57 with an even detection range and an even detection range that is not used. Therefore, the cost of the detection unit 57 can be suppressed.

<Second embodiment>
The second embodiment shown in FIG. 4 is a modification of the first embodiment. In the power converter 1 according to the second embodiment, the configurations of the sensor unit 50 and the control circuit section 60 (see FIG. 1) are different from those in the first embodiment.

The sensor unit 50 of the second embodiment includes a third branch conductive member 51 instead of the non-detection conductive member 56 of the first embodiment. The third branched conductive member 51 corresponds to part of the W-phase output line 6W, like the non-detected conductive member 56 in the first embodiment. That is, the sensor unit 50 of the second embodiment has three branch conductive members 51 corresponding to each phase of the three-phase alternating current.

Further, the sensor unit 50 of the second embodiment is provided with six detection sections 57 by adding the two detection sections 57 . The added two detection portions 57 correspond to the two branch current paths 55 belonging to the third branch conductive member 51, respectively. In the sensor unit 50 of the second embodiment, the two additional detectors 57 can directly detect the controlled current flowing through the W-phase output line 6W.

In the control circuit section 60 of the second embodiment, the functions of the control section 63 are partially different from those of the first embodiment. The control unit 63 of the second embodiment is configured to continue control using the branch current values of the remaining phases without using the branch current value of the phase in which an abnormality has been detected. That is, the phase in which the abnormality is detected is regarded as the phase corresponding to the non-detected conductive member 56, and control is continued by performing the same processing as the control unit 63 in the first embodiment.

[Summary of Second Embodiment]
According to the above configuration, similarly to the first embodiment, the power conversion device 1 can detect an abnormality in the shunt ratio and suppress a decrease in accuracy of the current to be controlled.

Abnormalities in branch current values also include abnormalities in which the total calculated control target current value deviates from the actual current due to a deviation between the actual current and the detected value due to an abnormality in the detection unit 57 . The control unit 63 of the present embodiment controls each phase using the control target current detected by the detection unit 57 in which no branch current value abnormality has occurred. Therefore, even when an abnormality occurs in the branch current value due to an abnormality in the detection unit 57, the power converter 1 can continue to control the current to be controlled while suppressing deterioration in accuracy.

<Other embodiments>
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and the following modifications are also included in the technical scope of the present disclosure. Various changes can be made within a range that does not deviate. In the following description, the elements having the same reference numerals as the reference numerals used so far are the same as the elements having the same reference numerals in the previous embodiments unless otherwise specified. Moreover, when only part of the configuration is described, the previously described embodiments can be applied to the other portions of the configuration.

In the first embodiment described above, the non-detection conductive member 56 is positioned at the end in the arrangement direction of the busbars within the sensor unit 50 . However, the non-detecting conductive member 56 may be arranged intermediate the two branch conductive members 51 . Further, the non-detection conductive member 56 may have a shape having a branch section 54 like the branch conductive member 51 if the corresponding detection portion 57 is not provided. In other words, when a plurality of branch sections 54 exist, if detection units 57 are provided in all of the branch current paths 55 included in at least one branch section 54, detection units 57 are provided in the other branch sections 54. There may be branch current paths 55 without

In the above-described embodiment, the branch sections 54 are formed in line symmetry, and the current to be controlled is divided substantially equally to each branch current path. However, the shape of the branch section 54 and the division ratio can be changed as appropriate.

In the second embodiment described above, when an abnormality in the branch current value is detected, the monitoring unit 62 does not specify which abnormality is present, and continues to control the control unit 63 based on the total value. rice field. However, the monitoring unit 62 can be configured to specify which abnormality is detected when an abnormality in the branch current value is detected. That is, if an abnormality is detected and the total value of the controlled current values for the three phases based on the sum of the branch current values is zero, it can be determined that there is an abnormality in the shunt ratio and not an abnormality in the detection unit 57. . On the other hand, if an abnormality is detected and the sum of the values for the three phases is not zero, it can be determined that there is an abnormality in the detector 57 rather than an abnormality in the shunt ratio.

Further, in such a configuration, the control unit 63 can adopt a configuration in which the processing of the control unit 63 is changed according to the identified abnormality to continue driving the motor generator 3 . That is, when it is determined that there is an abnormality in the division ratio, the control can be continued according to the values of the three currents to be controlled calculated by summing the branch current values individually for the three phases. On the other hand, when it is determined that the detection unit 57 is abnormal, control may be continued in the same manner as in the second embodiment. In addition, in the case of an abnormality in the detection unit 57, the monitoring unit 62 detects the side of the two detection units 57 in which the abnormality is not occurring based on the current to be controlled estimated from the other two phases in which the abnormality is not occurring and the current division ratio. can be specified. If the side on which no abnormality has occurred is specified, the control section 63 estimates the current to be controlled based on the detection value and the current division ratio of the detection section 57 on the side on which no abnormality has occurred, and continues the control. good.

In the above-described embodiment, each branch current path 55 is provided with one detection unit 57 . However, one branch current path 55 may be provided with a plurality of detectors 57 . According to such a configuration, it is possible to accurately identify the pattern of the abnormality that has occurred by combining the comparison with the detection unit 57 of the other branch current path 55 and the comparison with the detection unit 57 of the same branch current path 55. becomes.

1 power converter 51 branch conductive member 54 branch section 55 branch current path 56 undetected conductive member 57 detector 61 calculator 62 monitor 63 controller

Claims (3)

A member for passing a current to be controlled, which has a branch section (54) branched into a plurality of branch current paths (55), and divides the current to be controlled at a predetermined split ratio to flow through each of the branch current paths. a branch conductive member (51);
a plurality of detection units (57) provided at least one for each of the branch current paths and detecting the strength of the magnetic field corresponding to the current flowing through the corresponding branch current path;
a calculation unit (61) for calculating a branch current value flowing through each of the branch current paths based on the detection value of each of the detection units;
a monitoring unit (62) for monitoring abnormalities in the branch current values by comparing the branch current values of the plurality of branch current paths;
a control unit (63) for controlling the controlled current based on the value of the controlled current calculated by summing the branch current values ;
Three branch conductive members are provided corresponding to each phase of a three-phase alternating current,
Further, if the monitoring unit determines that an abnormality has occurred in the branch current value in any of the branch conductive members, and if the total of the three phases of the current to be controlled is zero, the division ratio is reduced. A power conversion device that judges that there is an abnormality, and judges that the detection unit is abnormal if the total of the three phases of the currents to be controlled is not zero . When the monitoring unit determines that an abnormality has occurred in the branch current value in any of the branch conductive members, the control unit calculates separately for each of the three phases if the branch current value is abnormal. control is continued based on the value of the current to be controlled that has been detected, and if there is an abnormality in the detection unit, the controlled object flowing through the three branch conductive members based on the value of the controlled current to another of the branch conductive members 2. The power converter according to claim 1, which controls current. The power converter according to any one of claims 1 and 2 , wherein the branch conductive member equally divides the controlled current to each of the branch current paths included in the branch section.

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