Power conversion apparatus and power conversion system

Abstract

To provide a power conversion apparatus in which an abnormality in a current path can be detected.SOLUTION: A power conversion apparatus includes an inverter circuit 20 functioning as a booster circuit and a motor 30, and is formed to be connectable with a charging stand 400 and a battery 200. The power conversion apparatus includes an external connection relay 52 that is an electric connection port for the charging stand 400, two transform wires 70, 80, 84 electrically connecting the external connection relay and a power source via the booster circuit, and a bypass wire 90 bypassing the booster circuit. In addition, the power conversion apparatus includes sensor devices 40 disposed on a first current path that is one of transform current paths and is provided with branch points 85, 86 of a bypass current path and on a second current path that is the other one of the transform current paths and is provided with no branch point. The sensor devices output electric signals according to a first current flowing between the external connection relay-side branch point 85 of the first current path and the booster circuit and a second current flowing through the second current path.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a power conversion device and a power conversion system. [Background technology]

[0002] One example of a power conversion device is a motor drive system disclosed in Patent Document 1. The motor drive system includes a battery and an inverter that converts DC power stored in the battery into three-phase AC power and provides it to the motor. The motor drive system is also configured to be connectable to a charging facility. The motor drive system is configured to selectively use a first charging mode in which external charging power is directly provided to the battery, and a second charging mode in which the external charging power is provided to the neutral point of the motor, and then boosted by controlling a switching element of the inverter to provide the power to the battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-40853 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a motor drive system, an abnormality may occur in the current path. In addition, in a motor drive system, if an abnormality occurs in the current path, there is a risk that a malfunction may occur in the charging equipment.

[0005] One disclosed object is to provide a power conversion device capable of detecting an abnormality in a current path. Another disclosed object is to provide a power conversion system capable of detecting an abnormality in a current path. [Means for solving the problem]

[0006] The power conversion device disclosed herein is A power conversion device including a transformer circuit (20, 30) and connectable to an external device (400) and a power source (200), A connection terminal (52) which is an electrical connection port with an external device; Two transformer current paths (70, 80, 84) on the high potential side and the low potential side that electrically connect the connection terminal and the power source via a transformer circuit; a bypass current path (90) which is a current path branched off from one of the two transformer current paths and bypasses the transformer circuit, and electrically connects and disconnects the connection terminal and the power source; a sensor device (40) provided in a first current path which is one of two current paths for transformation and has a branch point of a bypass current path, and a second current path which is the other of the two current paths for transformation and does not have a branch point; The sensor device is characterized by outputting an electrical signal according to a first current flowing between a branch point on the connection terminal side in the first current path and the transformer circuit, and a second current flowing through the second current path.

[0007] In the power conversion device configured as described above, the first current and the second current differ when the transformation current path and the bypass current path are normal and when an abnormality occurs in the transformation current path or the bypass current path. Therefore, the electric signal of the sensor device differs between the normal case and the abnormal case. Therefore, the power conversion device can detect that an abnormality occurs in the transformation current path or the bypass current path.

[0008] The power conversion system disclosed herein comprises: A power conversion system including a transformer circuit (20, 30) and a control device (10) that controls the transformer circuit, and connectable to an external device (400) and a power source (200), A connection terminal (52) which is an electrical connection port with an external device; Two transformer current paths (70, 80, 84) on the high potential side and the low potential side that electrically connect the connection terminal and the power source via a transformer circuit; a bypass current path (90) which is a current path branched off from one of the two transformer current paths and bypasses the transformer circuit, and electrically connects and disconnects the connection terminal and the power source; a sensor device (40) provided on a first current path which is one of two current paths for transformation and has a branch point of a bypass current path, and a second current path which is the other of the two current paths for transformation and does not have a branch point; the sensor device outputs an electric signal corresponding to a first current flowing between a branch point on a connection terminal side in the first current path and the transformer circuit and a second current flowing through the second current path; The control device includes: A current application step (S10) for performing a transforming operation of the transformer circuit; The method is characterized by comprising a determination step (S20) of determining the directions of the first current and the second current indicated by the electrical signal during the execution of the voltage transformation operation.

[0009] In the power conversion system configured as described above, the first current and the second current change depending on whether the transformation current path and the bypass current path are normal or not and whether an abnormality occurs in the transformation current path or the bypass current path. Therefore, the control device determines the directions of the first current and the second current indicated by the electric signal while performing the transformation operation. Therefore, the control device can detect whether an abnormality occurs in the transformation current path or the bypass current path based on the electric signal. In this way, the power conversion system can detect an abnormality in the current path.

[0010] The aspects disclosed in this specification adopt different technical means to achieve their respective objectives. The claims and the parenthetical symbols described in this section are illustrative of the corresponding relationship with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the following detailed description and the attached drawings. [Brief description of the drawings]

[0011] [Figure 1] 1 is a circuit diagram showing a schematic configuration of a power conversion system. [Diagram 2] FIG. 2 is a plan view showing a schematic configuration of the sensor device. [Diagram 3]FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 4 is a flowchart showing a current application process of an ECU. [Diagram 5] 4 is a flowchart showing a determination process of an ECU. [Figure 6] FIG. 11 is a circuit diagram showing a schematic configuration of a power conversion system according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Embodiment) Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, the other parts of the configuration may be applied by referring to the other embodiment described previously.

[0013] <Power conversion system> A power conversion system 100 will be described with reference to Fig. 1. Fig. 1 illustrates the power conversion system 100 in a state in which a charging stand 400 is connected. The charging stand 400 corresponds to a charging device.

[0014] The power conversion system 100 is configured to be mountable on, for example, a moving body. Examples of the moving body include automobiles, trains, and aircraft. In this embodiment, an automobile is used as an example of the moving body. Also, in this embodiment, an electric vehicle or a hybrid vehicle equipped with a rechargeable battery 200 is used as an example of the automobile. The automobile includes the power conversion system 100, the battery 200, a chassis 300, and the like. The battery 200 corresponds to a power source.

[0015] The power conversion system 100 includes a power conversion device and an ECU 10. The power conversion device includes an inverter circuit 20, a motor device 30, a sensor device 40, relays 51 to 53, capacitors 61 and 62, a wiring group, etc. The power conversion device may include an EMC filter, etc.

[0016] The power conversion system 100 is also configured to be electrically connectable to the battery 200 and a charging stand 400 (charging power source 410). The power conversion system 100 operates in a drive mode in which it drives the motor device 30, and a charge mode in which it is connected to the charging stand 400 and charges the battery 200. The state in which it is connected to the charging stand 400 can also be called an external connection mode. Naturally, in the drive mode, the power conversion system 100 is not connected to the charging stand 400. The battery 200 is mounted on the automobile together with the power conversion device 100. On the other hand, the charging stand 400 is provided outside the automobile. Therefore, the charging stand 400 can also be called an external device.

[0017] The battery 200 is the power source of the automobile. For example, a lithium ion battery can be used as the battery 200. In other words, the battery 200 can be used by repeatedly charging and discharging. In other words, the battery 200 can be called a storage battery, a rechargeable battery, or a battery. The battery 200 corresponds to a power source.

[0018] The charging stand 400 is a charging facility for charging the battery 200. The charging stand 400 includes a charging power source 410. The charging stand 400 also includes a charging cable, a computer, and the like. The charging cable is electrically connected to the charging power source 410. The charging cable is configured to be attachable to and detachable from the external connection relay 52. ​​The charging power source 410 is electrically connected to the power conversion system 100 by attaching the charging cable to the external connection relay 52. ​​The charging stand 400 corresponds to an external device.

[0019] The ECU 10 includes a processor such as a CPU, memory devices including RAM and ROM, input / output devices, etc. The input / output devices are electrically connected to the switching elements 21-26 of the inverter circuit 20, the relays 51-53, 91, the sensor device 40, etc.

[0020] The arithmetic processing device executes a program stored in the memory device. The arithmetic processing device executes arithmetic processing according to the program. The arithmetic processing device executes arithmetic processing using data stored in the memory device, a sensor signal from the sensor device 40, and the like. The arithmetic processing device controls the switching elements 21-26, the relays 51-53, and the bypass relay 91 via the input / output device. Furthermore, the arithmetic processing device is configured to be electrically connectable to the charging stand 400 via the input / output device. In the following, the processing operations performed by the arithmetic processing device will be described as the processing operations of the ECU 10.

[0021] The processing operation of the ECU 10 will be described in detail later. The ECU 10 corresponds to a control device. The sensor signal corresponds to an electrical signal.

[0022] The inverter circuit 20 includes, as switching elements, a U-phase upper arm switch 21, a U-phase lower arm switch 22, a V-phase upper arm switch 23, a V-phase lower arm switch 24, a W-phase upper arm switch 25, and a W-phase lower arm switch 26. The motor device 30 includes a U-phase coil 31, a V-phase coil 32, a W-phase coil 33, and a neutral point 34. Here, a three-phase motor is adopted as an example of the motor device 30. However, the present disclosure is not limited thereto.

[0023] The U-phase upper arm switch 21 and the U-phase lower arm switch 22 are connected in series between a negative electrode side wiring 70 and a positive electrode side wiring 80. The U-phase upper arm switch 21 and the U-phase lower arm switch 22 are connected to the U-phase coil 31 via a U-phase wiring 81.

[0024] The V-phase upper arm switch 23 and the V-phase lower arm switch 24 are connected in series between a negative electrode side wiring 70 and a positive electrode side wiring 80. The V-phase upper arm switch 23 and the V-phase lower arm switch 24 are connected to the V-phase coil 32 via a V-phase wiring 82.

[0025] The W-phase upper arm switch 25 and the W-phase lower arm switch 26 are connected in series between a negative electrode side wiring 70 and a positive electrode side wiring 80. The W-phase upper arm switch 25 and the W-phase lower arm switch 26 are connected to the W-phase coil 33 via a W-phase wiring 83.

[0026] The negative electrode side wiring 70 and the positive electrode side wiring 80 can be electrically connected to the battery 200 via the relay 51. The negative electrode side wiring 70 is connected to the negative terminal of the battery 200 when the relay 51 is in the on state (closed state). The positive electrode side wiring 80 is connected to the positive terminal of the battery 200 when the relay 51 is in the on state. The negative electrode side wiring 70 and the positive electrode side wiring 80 are electrically cut off from the battery 200 when the relay 51 is in the off state (open state). A capacitor 61 is provided between the negative electrode side wiring 70 and the positive electrode side wiring 80. Furthermore, turning the battery 200 to the on state can be referred to as on control or closed control, and turning the battery 200 to the off state can be referred to as off control or open control.

[0027] A neutral point wiring 84 is connected to the neutral point of the motor device 30. The neutral point wiring 84 is configured to be paired with the negative side wiring 70. The negative side wiring 70 and the neutral point wiring 84 can be electrically connected to the charging power source 410 via the external connection relay 52. ​​The negative side wiring 70 is connected to the negative terminal of the charging power source 410 when the external connection relay 52 is in the on state. The neutral point wiring 84 is connected to the positive terminal of the charging power source 410 when the external connection relay 52 is in the on state. The negative side wiring 70 and the neutral point wiring 84 are electrically cut off from the charging power source 410 when the external connection relay 52 is in the off state. A capacitor 62 is provided between the negative side wiring 70 and the neutral point wiring 84. In addition, the negative side wiring 70 and the neutral point wiring 84 may be provided with a fuse that melts when an overcurrent flows.

[0028] As described above, the relay 51 electrically connects and disconnects the charging stand 400 and the battery 200. The relay 51 corresponds to a switching device. The external connection relay 52 is an electrical connection port with the charging stand 400. The external connection relay 52 corresponds to a connection terminal. The external connection relay 52 can also be said to be an inlet. A neutral point relay 53 is provided in the neutral point wiring 84.

[0029] Each of the switching elements 21 to 26 is controlled by the ECU 10. The ECU 10 controls each of the switching elements 21 to 26 differently between the drive mode and the charge mode.

[0030] In the drive mode, the inverter circuit 20 supplies power from the battery 200 to the motor device 30. The motor device 30 is driven by the inverter circuit 20 to generate a rotational drive force. The drive force generated by the motor device 30 is transmitted to, for example, the drive wheels of the automobile.

[0031] On the other hand, in the charging mode, the inverter circuit 20 and the motor device 30 operate as a boost circuit. The inverter circuit 20 and the motor device 30 boost the voltage of the charging power source 410 and supply it to the battery 200. The inverter circuit 20 and the motor device 30 correspond to a transformer circuit. Hereinafter, the inverter circuit 20 and the motor device 30 are also referred to as a transformer circuit. The voltage of the charging power source 410 is also referred to as a charging voltage.

[0032] The negative side wiring 70, the positive side wiring 80, and the neutral point wiring 84 are wiring for electrically connecting the external connection relay 52 and the battery 200 via the transformer circuit. The negative side wiring 70, the positive side wiring 80, and the neutral point wiring 84 correspond to a current path for transformation. The positive side wiring 80 and the neutral point wiring 84 correspond to a current path for transformation on the high potential side. The negative side wiring 70 corresponds to a current path for transformation on the low potential side.

[0033] Hereinafter, the negative electrode side wiring 70, the positive electrode side wiring 80, and the neutral point wiring 84 are collectively referred to as the transformer wiring. The positive electrode side wiring 80 and the neutral point wiring 84 are collectively referred to as the high potential wiring. The negative electrode side wiring 70, the positive electrode side wiring 80, the phase wirings 81 to 83, and the neutral point wiring 84 are part of a wiring group.

[0034] Furthermore, the power conversion system 100 can also charge the battery 200 in the charging mode without going through a transformer circuit. That is, the charging mode includes a boost mode in which the charging voltage is boosted by the transformer circuit and supplied to the battery 200, and a bypass mode in which the charging voltage is supplied to the battery 200 without being boosted. For this purpose, the power conversion system 100 includes a bypass wiring 90. The bypass wiring 90 corresponds to a bypass current path.

[0035] The bypass wiring 90 is a current path that branches off from the high potential wiring and bypasses the transformer circuit. A first branch point 85 and a second branch point 86 are connection points of the bypass wiring 90 with the high potential wiring. The first branch point 85 is provided in the neutral point wiring 84. The second branch point 86 is provided in the positive electrode side wiring 80.

[0036] The bypass wiring 90 is provided with a bypass relay 91. Thus, the bypass wiring 90 is configured to be able to electrically connect and disconnect the external connection relay 52 and the battery 200. The bypass relay 91 is controlled to an off state in the boost mode, and is controlled to an on state in the bypass mode.

[0037] In this embodiment, as an example, the high potential wiring is provided with branch points 85 and 86. Therefore, the high potential wiring corresponds to a first current path. On the other hand, the negative electrode side wiring 70 corresponds to a second current path.

[0038] In the present embodiment, as an example, a bypass wiring 90 branched from the high potential wiring is used. However, the present disclosure is not limited to this. The bypass wiring 90 may be branched from the negative electrode side wiring 70. In this case, the high potential wiring corresponds to the second current path, and the negative electrode side wiring 70 corresponds to the first current path.

[0039] The sensor device 40 is provided on the high potential wiring and the negative side wiring 70. The sensor device 40 outputs a sensor signal corresponding to the current flowing through the high potential wiring and the negative side wiring 70. The sensor device 40 outputs a sensor signal corresponding to a first current flowing between a first branch point 85 in the neutral point wiring 84 and the transformer circuit, and a second current flowing through the negative side wiring 70. The first branch point 85 is a branch point on the external connection relay 52 side of the neutral point wiring 84. The first current can also be called a neutral point current. The second current can also be called an N current.

[0040] The sensor device 40 is provided to detect leakage current or the like in the power conversion device. Furthermore, the sensor device 40 is provided to detect whether or not an abnormality occurs in the voltage transformation wiring or the bypass wiring 90. In other words, the sensor device 40 can be used to detect whether or not an abnormality occurs in the voltage transformation wiring or the bypass wiring 90.

[0041] Here, the sensor device 40 will be described in detail with reference to Fig. 2 and Fig. 3. As shown in Fig. 2 and Fig. 3, the sensor device 40 includes a Hall IC 41 and a core 42. The Hall IC 41 and the core 42 may be integrally sealed with an electrically insulating resin member. The sensor device 40 may also include a wiring board electrically connected to the Hall IC 41. The Hall IC 41 is electrically connected to the ECU 10.

[0042] The core 42 is provided so as to integrally surround the neutral point wiring 84 and the negative pole side wiring 70. The core 42 collects magnetic flux caused by current flowing through the neutral point wiring 84 and the negative pole side wiring 70. The core 42 corresponds to a magnetic flux collecting portion. The core 42 is also referred to as a magnetic core or a magnetic material core. The core 42 is provided with a gap 42g. The gap 42g corresponds to a clearance portion.

[0043] The Hall IC 41 outputs an electric signal (sensor signal) according to the magnetic state. It can also be said that the sensor device 40 outputs a sensor signal according to the magnetic flux due to the first current and the magnetic flux due to the second current. The magnetic state here is the magnetic flux density. The sensor signal here is the Hall voltage.

[0044] The Hall IC 41 includes a Hall element and a processing circuit that processes a signal output from the Hall element. The processing circuit includes an amplifier circuit that amplifies the signal. The Hall IC 41 is disposed in the gap 42g. That is, the Hall IC 41 outputs a sensor signal according to the magnetic state of the gap 42g. The Hall IC 41 corresponds to a magnetic detection element.

[0045] In this embodiment, a Hall IC 41 is used as the magnetic detection element. However, the present disclosure is not limited to this, and a magnetic detection element including an MR element or a TMR element can also be used. MR is an abbreviation for Magneto Resistance. TMR is an abbreviation for Tunneling Magneto Resistance.

[0046] Here, the current of the power conversion system 100 when charging in the boost mode will be described with reference to Fig. 1. Note that the bypass relay 91 in the boost mode is in the off state. However, Fig. 1 illustrates the bypass relay 91 in the on state for convenience.

[0047] Under normal conditions, current flows through the power conversion system 100 as shown by the solid arrows. Therefore, the neutral point wiring 84 and the negative pole side wiring 70 have opposite current flows. In other words, the first current and the second current have opposite directions. The first current flows from the charging stand 400 side to the battery 200 side. On the other hand, the second current flows from the battery 200 side to the charging stand 400 side. The first current and the second current have the same current value.

[0048] Therefore, as shown in FIG. 3, the magnetic flux due to the current flowing through the neutral point wiring 84 and the magnetic flux due to the current flowing through the negative pole side wiring 70 cancel each other out. In other words, the magnetic fluxes to the Hall IC 41 cancel each other out. Therefore, the Hall IC 41 does not output a sensor signal. Alternatively, the Hall IC 41 outputs an electric signal whose magnetic flux density can be regarded as zero. It can also be said that the Hall IC 41 outputs a sensor signal indicating that the first current and the second current are in opposite directions.

[0049] In the power conversion system 100, if the bypass relay 91 is mistakenly turned on due to sticking or the like, a current flows as shown by the dashed-dotted arrow. In addition, in the power conversion system 100, if a leakage current occurs and a ground fault occurs via the chassis 300 or the like, a current flows as shown by the dashed-two-dotted arrow. In other words, if a ground fault occurs in the transformation wiring, a current flows as shown by the dashed-two-dotted arrow. In this way, if an abnormality occurs in the transformation wiring or the bypass wiring 90, the relationship between the direction of the first current and the direction of the second current differs from that in the normal state.

[0050] Therefore, when an abnormality occurs in the bypass current path, the Hall IC 41 outputs a sensor signal indicating that the first current and the second current are in the same direction, or a sensor signal indicating that only one of the first current and the second current is flowing. In this embodiment, only the second current flows. On the other hand, when an abnormality occurs in the transformer current path, the Hall IC 41 outputs a sensor signal indicating that the first current and the second current are in the same direction. In this way, the Hall IC 41 outputs a sensor signal only when an abnormality occurs in the transformer wiring or the bypass wiring 90.

[0051] It can also be said that a difference occurs between the first current and the second current when an abnormality occurs in the transformer wiring or the bypass wiring 90. Therefore, the Hall IC 41 outputs a sensor signal only when a difference occurs between the first current and the second current.

[0052] <Processing Operation> The processing operation of the ECU 10 will be described with reference to Figures 4 and 5. The ECU 10 starts the flowchart shown in Figure 4 at the timing to start charging the battery 200. The ECU 10 determines that it is time to start charging when it receives a command signal to start charging from the charging stand 400. The ECU 10 may also determine that it is time to start charging when it detects that the external connection relay 52 and the charging stand 400 are connected, for example.

[0053] In step S10, energization is started (energization step). The ECU 100 controls the switching elements 21-26 to operate the inverter circuit 20 and the motor device 30 as a boost circuit. The ECU 10 also controls the relays 51 and 53 to an on state, and controls the bypass relay 91 to an off state. In this way, the ECU 10 executes the transforming operation of the transformer circuit. As a result, the battery 200 is charged by the boosted charging voltage.

[0054] In step S11, it is determined whether or not power supply is stopped. The ECU 10 determines that power supply is stopped, for example, when a charging stop instruction signal is received from the charging stand 400, or when the connection between the external connection relay 52 and the charging stand 400 is released. If the ECU 10 determines that power supply is stopped, the flow chart of FIG. 4 is terminated. On the other hand, if the ECU 10 does not determine that power supply is stopped, the ECU 10 repeatedly executes step S11. In other words, the ECU 10 executes the voltage conversion operation until it determines that power supply is stopped.

[0055] The ECU 10 starts the flowchart shown in Fig. 5 during the execution of the voltage transformation operation. The ECU 10 starts the flowchart shown in Fig. 5, for example, at predetermined time intervals. The ECU 10 may also start the flowchart shown in Fig. 5 by interruption when an event occurs.

[0056] In step S20, it is determined whether the first current and the second current are in the opposite directions (determination step). The ECU 10 checks the directions of the first current and the second current indicated by the sensor signal. That is, the ECU 10 determines whether an abnormality has occurred in the voltage transformation wiring or the bypass wiring 90 based on the sensor signal from the sensor device 40.

[0057] When the sensor signal is not output, the ECU 10 determines that the first current and the second current indicated by the sensor signal are in the opposite directions. When the ECU 10 determines that the first current and the second current are in the opposite directions, the ECU 10 does not determine that an abnormality has occurred and ends the flow chart of Fig. 5. It can also be said that the ECU 10 determines that the transformer wiring or the bypass wiring 90 is normal when the sensor signal is not output.

[0058] On the other hand, when the sensor signal is output, the ECU 10 determines that the first current and the second current indicated by the sensor signal have the same direction. When the ECU 10 determines that the first current and the second current have the same direction, it determines that an abnormality has occurred and proceeds to step S21. Note that, when the sensor signal is output, the ECU 10 may determine that only one of the first current and the second current is flowing and that an abnormality has occurred. It can also be said that, when the sensor signal is output, the ECU 10 determines that an abnormality has occurred in the transformation wiring or the bypass wiring 90.

[0059] In step S21, charging is stopped. The ECU 10 stops charging of the battery 200. The ECU 10, for example, controls the relay 53 to be in the off state. When the relay 53 is in the off state, the charging stand 400 and the battery 200 are electrically disconnected. In this case, the ECU 10 can stop charging within the power conversion system 100.

[0060] Furthermore, the ECU 10 outputs a stop request signal indicating the stop of charging to the charging stand 400. The charging stand 400 stops the supply of power in response to the stop request signal. In this case, the supply of power itself from the charging stand 400 to the power conversion system 100 can be stopped.

[0061] <Effects> In the power conversion device configured as described above, the first current and the second current differ between when the transformation wiring and the bypass wiring 90 are normal and when an abnormality occurs in the transformation wiring or the bypass wiring 90. Therefore, the sensor signal of the sensor device 40 differs between the normal case and the abnormal case. Therefore, the power conversion device can detect that an abnormality occurs in the transformation wiring or the bypass wiring 90.

[0062] It can also be said that the power conversion device is configured such that the sensor device 40 detects an abnormality in the transformation wiring or the bypass wiring 90 based on the first current and the second current. It can also be said that the power conversion device is configured such that the sensor device 40 outputs an abnormality detection signal for detecting an abnormality in the transformation wiring or the bypass wiring 90 in accordance with the first current and the second current.

[0063] In addition, the first current and the second current are different in the power conversion system when it is normal and when an abnormality occurs as described above. Therefore, the ECU 10 determines the directions of the first current and the second current indicated by the sensor signal during the execution of the voltage transformation operation. Therefore, the ECU 10 can detect whether or not an abnormality occurs in the transformation wiring or the bypass wiring 90 based on the sensor signal. In this way, the power conversion system can detect an abnormality in the current path.

[0064] In this embodiment, an example is adopted in which the inverter circuit 20 and the motor device 30 are used as a transformer circuit. However, the present disclosure is not limited to this. The power conversion device 100 can also be configured to include a transformer circuit having a switching element that is not a part of the inverter circuit 20 and a coil that is not a part of the motor device 30. In other words, the power conversion device 100 can also be configured to include a transformer circuit having only one coil and only one switching element.

[0065] (Variation 1) 6, the power conversion device of the modified example may include a first sensor 40a and a second sensor 40b. The first sensor 40a is provided between a first branch point 85 in a neutral point wiring 84 and the transformer circuit. The second sensor 40b is provided in a negative electrode side wiring 70.

[0066] The first sensor 40a and the second sensor 40b each include a Hall IC and a core, similar to the sensor device 40. The core of the first sensor 40a is provided so as to surround only the neutral point wiring 84 of the wiring group. The core of the second sensor 40b is provided so as to surround only the negative electrode side wiring 70 of the wiring group.

[0067] The first sensor 40a outputs a first signal corresponding to the first current as a sensor signal. The second sensor 40b outputs a second signal corresponding to the second current as a sensor signal. Therefore, the first sensor 40a and the second sensor 40b output the first signal and the second signal even if the voltage transformation wiring and the bypass wiring 90 are normal. In other words, when the voltage transformation wiring and the bypass wiring 90 are normal, the first signal and the second signal are signals indicating that the directions of the first current and the second current are opposite to each other.

[0068] On the other hand, when an abnormality occurs in the transformer wiring or the bypass wiring 90, the first signal and the second signal indicate that the first current and the second current have the same direction, or indicate that only one of the first current and the second current is flowing.

[0069] Then, the ECU 10 judges whether the first current and the second current are in the opposite directions based on the first signal and the second signal (S20). Therefore, the power conversion device of the modified example can achieve the same effects as those of the above embodiment. The same also applies to a power conversion system including the power conversion device of the modified example.

[0070] Furthermore, the power conversion system 100 may be electrically connected to a house or the like as an external device instead of the charging stand 400. In this case, the external connection relay 52 is connected to an outlet in the house. Then, the power conversion system 100 is electrically connected to a storage battery, a distribution board, or the like provided in the house.

[0071] The power conversion system 100 supplies (feeds) the power of the battery 200 to a storage battery of the house, etc., while being electrically connected to the house. In other words, the power conversion system 100 operates in a power feeding mode.

[0072] In the power supply mode, the inverter circuit 20 and the motor device 30 function as a step-down circuit. The inverter circuit 20 and the motor device 30 step down the voltage of the battery 200 and supply it to a storage battery or the like.

[0073] In this case, in step S10, the EUC 100 controls the switching elements 21-26 to operate the inverter circuit 20 and the motor device 30 as a step-down circuit (transformer circuit). The ECU 10 also controls the relays 51 and 53 to be in the on state, and controls the bypass relay 91 to be in the off state. In this manner, the ECU 10 executes the transformation operation of the transformer circuit. As a result, the stepped-down voltage of the battery 200 is supplied to a storage battery or the like. Note that even in the power supply mode, power may be supplied via the bypass wiring 90 without being stepped down.

[0074] The above describes the preferred embodiment of the present disclosure. However, although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more than one element, or less than one element are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0075] 10...ECU, 20...inverter circuit, 21...U-phase upper arm switch, 22...U-phase lower arm switch, 23...V-phase upper arm switch, 24...V-phase lower arm switch, 25...W-phase upper arm switch, 26...W-phase lower arm switch, 30...motor device, 31...U-phase coil, 32...V-phase coil, 33...W-phase coil, 34...neutral point, 40...sensor device, 40a...first sensor, 40b...second sensor, 41...Hall I C, 42...core, 42g...gap, 51...relay, 52...external connection relay, 53...neutral point relay, 61, 62...capacitor, 70...negative side wiring, 80...positive side wiring, 81...U phase wiring, 82...V phase wiring, 83...W phase wiring, 84...neutral point wiring, 85...first branch point, 86...second branch point, 90...bypass wiring, 91...bypass relay, 200...battery, 300...chassis, 400...charging stand, 410...charging power source

Claims

1. A power conversion device including a transformer circuit (20, 30) and connectable to an external device (400) and a power source (200), A connection terminal (52) which is an electrical connection port with the external device; two transformer current paths (70, 80, 84) on a high potential side and a low potential side that electrically connect the connection terminal and the power source via the transformer circuit; a bypass current path (90) that branches off from one of the two transformer current paths and bypasses the transformer circuit, electrically connecting and disconnecting the connection terminal and the power source; a sensor device (40) provided in a first current path which is one of the two transforming current paths and in which a branch point of the bypass current path is provided, and a second current path which is the other of the two transforming current paths and in which the branch point is not provided, The sensor device is a power conversion device that outputs an electrical signal corresponding to a first current flowing between the branch point on the connection terminal side in the first current path and the transformer circuit and a second current flowing through the second current path.

2. 2. The power conversion device according to claim 1, wherein, when an abnormality occurs in the transformation current path or the bypass current path, the sensor device outputs the electrical signal indicating that the first current and the second current have the same direction or that only one of the first current and the second current is flowing.

3. The sensor device includes: a magnetic flux collector (42) that integrally surrounds the first current path and the second current path and collects magnetic flux caused by currents flowing through the first current path and the second current path and that has a gap (42g); a magnetic detection element (41) disposed in the gap and outputting the electric signal according to the magnetic state of the gap; The power conversion device according to claim 2 , wherein the magnetic detection element outputs the electric signal only when an abnormality occurs in the transformation current path or the bypass current path.

4. The sensor device includes a first sensor (40a) provided between the branch point on the connection terminal side in the first current path and the transformer circuit, and a second sensor (40b) provided in the second current path, The power conversion device according to claim 2 , wherein, as the electrical signal, the first sensor outputs a first signal corresponding to the first current, and the second sensor outputs a second signal corresponding to the second current.

5. The power conversion device according to claim 1 , further comprising a control device (10) that determines whether or not an abnormality has occurred in the transformation current path or the bypass current path based on the electrical signal from the sensor device.

6. A power conversion system comprising a transformer circuit (20, 30) and a control device (10) that controls the transformer circuit, and which is connectable to an external device (400) and a power source (200), A connection terminal (52) which is an electrical connection port with the external device; two transformer current paths (70, 80, 84) on a high potential side and a low potential side that electrically connect the connection terminal and the power source via the transformer circuit; a bypass current path (90) that branches off from one of the two transformer current paths and bypasses the transformer circuit, electrically connecting and disconnecting the connection terminal and the power source; a sensor device (40) provided on a first current path which is one of the two transforming current paths and has a branch point of the bypass current path, and a second current path which is the other of the two transforming current paths and does not have the branch point; the sensor device outputs an electric signal corresponding to a first current flowing between the branch point on the connection terminal side in the first current path and the transformer circuit and a second current flowing through the second current path, The control device includes: A current application step (S10) for performing a transforming operation of the transformer circuit; and a determination step (S20) of determining directions of the first current and the second current indicated by the electrical signal during the execution of the voltage transformation operation.

7. a switching device (51) for electrically connecting and disconnecting the external device and the power source, The power conversion system according to claim 6 , wherein the control device, when determining that an abnormality has occurred, controls the switching device to open, thereby electrically disconnecting the external device from the power source.

8. The external device is a charging device for charging the power source, The power conversion system according to claim 6 or 7, wherein the control device outputs a stop request signal indicating that charging is to be stopped to the external device when it is determined that an abnormality has occurred.

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