JP2017139870A - Power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion device which prevents influences of such abnormality of raising an output voltage that a short-circuit fault of a switching element occurs, from being propagated even if such abnormality occurs in a drive power source.SOLUTION: A power conversion device 100A comprises multiple switching element modules 1-3; multiple drive circuits 11-16 and multiple drive power sources 71-73. Each of the multiple drive power sources 71-73 includes two secondary windings W21 and W22 that are output parts. The drive circuit 11 driving a switching element S1 at one side in the switching element module 1 is connected to the secondary winding W21 of the drive power source 71 separate from the drive power source 73 to which the secondary winding W22 connected to the drive circuit 12 driving a switching element S2 at the other side connected to the switching element S1 at the one side in series belongs.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power conversion device.

  FIG. 6 is a circuit diagram showing a configuration of a power conversion device 200 which is an example of a conventional power conversion device. The power conversion device 200 is an inverter device that converts DC power into AC power and outputs the AC power. The power conversion device 200 includes switching elements S1 to S6, freewheeling diodes D1 to D6, drive circuits 11 to 16, drive power supplies 41 to 43, and a DC power supply 8. Each of the switching elements S1 to S6 is, for example, an IGBT (Insulated Gate Bipolar Transistor). The switching element S1 and the switching element S2 are connected in series between a high potential side input power line connected to the positive electrode of the DC power source 8 and a low potential side input power source line connected to the negative electrode of the DC power source 8. ing. More specifically, the collector of the switching element S 1 is connected to the input power line on the high potential side of the DC power supply 8. The emitter of the switching element S2 is connected to the input power line on the low potential side of the DC power supply 8. The emitter of the switching element S1 is connected to the collector of the switching element S2. A connection point between the switching element S1 and the switching element S2 is a U-phase output terminal. A free-wheeling diode D1 is connected between the emitter and collector of the switching element S1, and a free-wheeling diode D2 is connected between the emitter and collector of the switching element S2. Switching element S1 and free-wheeling diode D1 constitute a U-phase upper arm, and switching element S2 and free-wheeling diode D2 constitute a U-phase lower arm. The U-phase upper arm and the U-phase lower arm constitute a U-phase switching element module 1. Similarly, switching element S3 and free-wheeling diode D3 constitute a V-phase upper arm, and switching element S4 and free-wheeling diode D4 constitute a V-phase lower arm. The V-phase upper arm and the V-phase lower arm constitute a V-phase switching element module 2. Switching element S5 and free-wheeling diode D5 constitute a W-phase upper arm, and switching element S6 and free-wheeling diode D6 constitute a W-phase lower arm. The W-phase upper arm and the W-phase lower arm constitute a W-phase switching element module 3.

  A driving circuit 11 is connected to the switching element S1, a driving circuit 12 is connected to the switching element S2, a driving circuit 13 is connected to the switching element S3, and a driving circuit 14 is connected to the switching element S4. A drive circuit 15 is connected to S5, and a drive circuit 16 is connected to the switching element S6. More specifically, the drive circuits 11 to 16 are connected between the gates and emitters of the switching elements S1 to S6. The drive circuits 11 to 16 are circuits that turn on / off the switching elements S1 to S6 by supplying a signal to the gates of the switching elements S1 to S6 to be connected in accordance with a control signal supplied from a control circuit (not shown).

  The drive power supply 41 is a power supply that supplies power for operating the drive circuit 11 to the drive circuit 11 and supplies power for operating the drive circuit 12 to the drive circuit 12. The drive power supply 42 is a power supply that supplies power for operating the drive circuit 13 to the drive circuit 13 and supplies power for operating the drive circuit 14 to the drive circuit 14. The drive power supply 43 is a power supply that supplies power for operating the drive circuit 15 to the drive circuit 15 and supplies power for operating the drive circuit 16 to the drive circuit 16. The drive power supplies 41 to 43 have the same configuration. Therefore, the configuration of the drive power supplies 41 to 43 will be described by taking the drive power supply 41 as an example. The drive power supply 41 includes a transformer 21, a capacitor 22, a transistor 23, a control unit 24, a resistor R1, a resistor R2, and a feedback signal line 25.

  The transformer 21 has a primary winding W1, a secondary winding W21, and a secondary winding W22. The primary winding W1, the secondary winding W21 and the secondary winding W22 are coupled by a magnetic element such as an iron core or ferrite. One end of the primary winding W <b> 1 is connected to the positive electrode of the DC power supply 8, and the other end of the primary winding W <b> 1 is connected to the negative electrode of the DC power supply 8 via the transistor 23. Both ends of the secondary winding W21 are connected to the drive circuit 11. Both ends of the secondary winding W22 are connected to the drive circuit 12. As described above, the transformer 21 is an insulating unit that insulates the DC power supply 8 on the primary side from the drive circuits 11 and 12 on the secondary side. Further, in the transformer 21, the turns ratio between the primary winding W1 and the secondary winding W21 and the turns ratio between the primary winding W1 and the secondary winding W22 are substantially the same, and the secondary winding. The output of the line W21 and the output of the secondary winding W22 are substantially the same.

  The transistor 23 is, for example, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor; a field effect transistor having a metal-oxide film-semiconductor structure). A diode is connected between the drain and source of the transistor 23. One electrode of the capacitor 22 is connected to the positive electrode of the DC power supply 8, and the other electrode is connected to the negative electrode of the DC power supply 8.

  A resistor R1 and a resistor R2 are connected in series between both ends of the secondary winding W22. The resistors R1 and R2 are resistors that divide the voltage across the secondary winding W22. A connection point between the resistor R1 and the resistor R2 and the control unit 24 are connected by a feedback signal line 25. Thereby, a feedback signal indicating the voltage divided by the resistors R1 and R2 is sent to the control means 24.

The control means 24 is an integrated circuit for power supply that supplies a signal to the gate of the transistor 23 to turn on / off the transistor 23. The control unit 24 controls on / off of the transistor 23 with reference to the feedback signal. When the transistor 23 is turned on / off, the voltage output from the secondary winding W22 and input to the drive circuit 12 is controlled to be constant. By controlling the input voltage of the drive circuit 12 to be constant, the voltage output from the secondary winding W21 and input to the drive circuit 11 is also controlled to be constant.
Such a power conversion device 200 is disclosed in Patent Document 1, for example.

  FIG. 7 is a circuit diagram showing an example of a specific configuration of the DC power supply 8 of FIG. The rectifier circuit 51 including a diode is a circuit that converts AC power supplied from the AC power source 56 into DC power. The DC power output from the rectifier circuit 51 is smoothed by the capacitor 52. Between the AC power source 56 and the rectifier circuit 51, AC fuses 53 to 55 are provided for each phase. The fuses 53 to 55 are blown when an overcurrent flows, and disconnect the circuit (the circuit after the rectifier circuit 51) subsequent to the fuses 53 to 55 from the AC power supply 56.

  FIG. 8 is a circuit diagram showing another example of the specific configuration of the DC power supply 8 of FIG. The battery 58 is composed of a large number of cells. The DC power output from the battery 58 is kept constant by the capacitor 52. A DC fuse 57 is provided between the positive electrode of the battery 58 and one electrode of the capacitor 52. The fuse 57 is blown when an overcurrent flows, and disconnects the circuit subsequent to the fuse 57 from the battery 58.

Japanese Patent No. 5369978

  In the power conversion device 200 of FIG. 6, it is assumed that the switching element S1 of the U-phase upper arm is off and the switching element S2 of the U-phase lower arm is on. In this state, it is assumed that the feedback signal supplied to the control unit 24 is maintained at “0” for the reason that the feedback signal line 25 is disconnected. The control means 24 determines that no power is supplied to the secondary winding W22 because the feedback signal is “0”, and determines that no power is supplied to the secondary winding W21 and the secondary winding W22. 23 is controlled on / off. As a result, power is supplied excessively to the secondary winding W21 and the secondary winding W22 even though the input voltages of the drive circuits 11 and 12 are actually controlled to be constant. Become. If power continues to be excessively supplied to the secondary winding W21 and the secondary winding W22, the input voltage of the drive circuit 11 and the input voltage of the drive circuit 12 increase. As the input voltage of the drive circuit 11 increases, the output voltage of the drive circuit 11 also increases, and the voltage applied between the gate and emitter of the switching element S1 increases. Similarly, when the input voltage of the drive circuit 12 increases, the output voltage of the drive circuit 12 also increases, and the voltage applied between the gate and the emitter of the switching element S2 increases.

  In the switching element S2 that is turned on, the collector and emitter are short-circuited. If an excessive voltage is applied between the gate and the emitter while the collector and the emitter are short-circuited, the collector-emitter breakdown voltage related to the gate-emitter voltage is reduced and applied between the collector and the emitter. Exceeds the collector-emitter breakdown voltage. As a result, the switching element S2 is short-circuited between the collector and the emitter. This short-circuit failure of the switching element S2 is a failure in which the collector-emitter is maintained in a short-circuited state regardless of the signal applied to the gate.

  Thereafter, when the switching element S1 is turned on, the collector-emitter breakdown voltage of the switching element S1 decreases, and the voltage applied between the collector and emitter exceeds the collector-emitter breakdown voltage. Thereby, following the switching element S2, the switching element S1 also causes a short-circuit failure between the collector and the emitter.

  When both the switching element S1 and the switching element S2 are short-circuited, the DC power supply 8 is short-circuited. When the specific configuration of the DC power supply 8 is the configuration shown in FIG. 7, the fuses 53 to 55 are blown by the short circuit of the DC power supply 8. When the specific configuration of the DC power supply 8 is the configuration shown in FIG. 8, the fuse 57 is blown by a short circuit of the DC power supply 8.

  Assume that a protection circuit is provided to prevent a short circuit between the collector and the emitter before the voltage applied between the collector and the emitter of the switching element S1 exceeds the collector-emitter breakdown voltage. By providing such a protection circuit, when the switching element S1 is turned on, the switching element S1 is immediately turned off before the switching element S1 is short-circuited. Even in such a configuration, the input voltage of the drive circuit 11 continues to rise, so that the input voltage of the drive circuit 11 may exceed the withstand voltage of the members constituting the drive circuit 11 and the drive circuit 11 may fail. is there. Depending on the failure of the drive circuit 11, there may be an abnormality in which an excessive voltage exceeding the withstand voltage is applied between the collector and the emitter of the switching element S1. When such an abnormality occurs, there is a possibility that a short circuit failure occurs between the collector and the emitter of the switching element S1 even if the above-described protection circuit is provided. When both the switching element S1 and the switching element S2 are short-circuited, the DC power supply 8 is short-circuited as described above.

  When an overcurrent that blows the fuses 53 to 55 flows to the DC power supply 8, the voltage of the AC power supply 56 may fluctuate, which may adversely affect other systems connected in parallel to the AC power supply 56. Further, if the fuses 53 to 55 are not properly blown, there is a possibility that smoke or fire may be generated due to overcurrent.

  As described above, in the power conversion device 200, when an abnormality occurs in which the output voltage of the drive power supply 41 increases, the switching element S2 and the switching element S1 are sequentially short-circuited and finally the fuses 53 to 55 or 57 are blown. As a result, the influence of the abnormality that the output voltage of the drive power supply 41 rises reaches the input power supply side. Although switching element S1 and switching element S2 were demonstrated to the example, it is the same also about switching element S3-S6.

  The present invention has been made in view of the above-described circumstances, and even when an abnormality that causes an output voltage rise that causes a short-circuit failure of a switching element in a drive power supply occurs, power conversion that does not affect the influence of the abnormality Providing equipment.

  In the power conversion device according to the present invention, the upper arm including the switching element and the lower arm including the switching element are connected in series between the input power supply lines, and one phase is configured with the connection point of the upper arm and the lower arm as the output terminal. A plurality of upper and lower arms. The power converter includes a plurality of drive circuits that are provided for each switching element of the upper and lower arms and that drive the switching elements of the upper and lower arms, and a plurality of drive power sources. In the power converter, at least one drive power source among the plurality of drive power sources includes a plurality of output units that output power. In this power converter, in any phase, the drive circuit that drives the switching element on one side of the upper and lower arms is connected to the drive circuit that drives the other switching element connected in series to the switching element on one side. The output unit of the drive power source to which the output unit belongs is connected.

  In the power conversion device according to the present invention, the drive circuit that drives the switching element on one side of the upper and lower arms and the drive circuit that drives the switching element on the other side are connected to separate drive power supplies. As a result, even if an abnormality in which the output voltage rises occurs in the drive power supply that supplies power to the drive circuit that drives the switching element on one side, and the switching element on the other side is short-circuited, the switching element on the other side If no abnormality occurs in the driving power supply that supplies power to the driving circuit to be driven, the switching element on the other side will not be short-circuited. Even if the switching element on one side is short-circuited, the switching element on the other side is not short-circuited. Therefore, the input power supply lines are not short-circuited, and the influence of the abnormality of the drive power supply does not affect the input power supply side.

  Therefore, in the power conversion device according to the present invention, even if an abnormality in which the output voltage rises that causes a short-circuit failure of the switching element occurs in the drive power supply, the influence of the abnormality does not spread.

It is a circuit diagram which shows the structure of 100 A of power converter devices by 1st Embodiment of this invention. It is a circuit diagram which shows the structure of power converter device 100B by 2nd Embodiment of this invention. It is a circuit diagram which shows the structure of 100 C of power converter devices by 3rd Embodiment of this invention. It is a circuit diagram which shows the structure of power converter device 100D by 4th Embodiment of this invention. It is a circuit diagram which shows the structure of the power converter device 100E by 5th Embodiment of this invention. It is a circuit diagram which shows the structure of the power converter device 200 which is an example of the conventional power converter device. 3 is a circuit diagram showing an example of a specific configuration of a DC power supply 8 in the power conversion device 200. FIG. FIG. 6 is a circuit diagram showing another example of a specific configuration of DC power supply 8 in power conversion device 200.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<First Embodiment>
FIG. 1 is a circuit diagram showing a configuration of a power conversion device 100A according to the first embodiment of the present invention. The power conversion device 100A of the present embodiment has a conventional combination shown in FIG. 6 in that the driving power sources 41 to 43 are replaced by driving power sources 71 to 73 and the connection between the driving power sources 71 to 73 and the driving circuits 11 to 16 is shown in FIG. Different from the power converter 200. The same components as those of the conventional power conversion device 200 are denoted by the same reference numerals and description thereof is omitted.

  Each of the drive power supplies 71 to 73 has the same configuration. The drive power supplies 71 to 73 differ from the drive power supplies 41 to 43 in that the resistor R1, the resistor R2, and the feedback signal line 25 are omitted. That is, the control means 24 of this embodiment controls on / off of the transistor 23 without referring to the feedback signal. This is because the ON / OFF control of the transistor 23 can be appropriately performed by appropriately combining the drive power supplies 71 to 73 and the drive circuits 11 to 16 without referring to the feedback signal.

  Each of the drive power supplies 71 to 73 has a transformer 21 including a secondary winding W21 and a secondary winding W22, similarly to the drive power supplies 41 to 43. Each of the secondary winding W21 and the secondary winding W22 is an output unit that outputs electric power. That is, each of the drive power supplies 71 to 73 includes two output units.

  In power converter 100A, both ends of secondary winding W21 of drive power supply 71 are connected to drive circuit 11 that drives switching element S1 of the U-phase upper arm, and both ends of secondary winding W22 of drive power supply 71 are connected. Is connected to a drive circuit 14 for driving the switching element S4 of the V-phase lower arm. Further, both ends of the secondary winding W21 of the driving power source 72 are connected to the driving circuit 13 that drives the switching element S3 of the V-phase upper arm, and both ends of the secondary winding W22 of the driving power source 72 are connected to the W phase. It is connected to a drive circuit 16 that drives the switching element S6 of the lower arm. Further, both ends of the secondary winding W21 of the drive power source 73 are connected to the drive circuit 15 that drives the switching element S5 of the W-phase upper arm, and both ends of the secondary winding W22 of the drive power source 73 are connected to the U phase. It is connected to the drive circuit 12 that drives the switching element S2 of the lower arm.

  With such a configuration, power is supplied to the drive circuit 12 of the switching element S2 from a drive power supply 73 that is separate from the drive power supply 71 that supplies power to the drive circuit 11 of the switching element S1. Similarly, power is supplied to the drive circuit 14 of the switching element S4 from a drive power supply 71 that is separate from the drive power supply 72 that supplies power to the drive circuit 13 of the switching element S3. Similarly, power is supplied to the drive circuit 16 of the switching element S6 from a drive power supply 72 that is separate from the drive power supply 73 that supplies power to the drive circuit 15 of the switching element S5.

  In the power conversion device 100A, even if an abnormality in which the output voltage of the drive power supply 71 increases and the switching elements S1 and S4 are short-circuited, the switching elements S2 and S3 do not occur if no abnormality occurs in the drive power supplies 72 and 73. Will not short circuit. For this reason, even if the switching elements S1 and S4 are short-circuited, the DC power supply 8 is short-circuited and the fuses 53 to 55 or 57 are not melted. That is, in the power conversion device 100A, the influence of the abnormality of the drive power supply 71 does not affect the switching elements S2 and S3 and the input power supply side.

  Similarly, in power conversion device 100A, even if an abnormality in which the output voltage of drive power supply 72 rises and switching elements S3 and S6 are short-circuited, if no abnormality occurs in drive power supplies 71 and 73, switching element S4 and S5 are not short-circuited. For this reason, even if the switching elements S3 and S6 are short-circuited, the influence of the abnormality of the drive power supply 72 does not affect the switching elements S4 and S5 or the input power supply side.

  Similarly, in power conversion device 100A, even if an abnormality in which the output voltage of drive power supply 73 increases and switching elements S5 and S2 are short-circuited, if no abnormality occurs in drive power supplies 71 and 72, switching element S6 and S1 are not short-circuited. For this reason, even if the switching elements S5 and S2 are short-circuited, the influence of the abnormality of the drive power supply 73 does not affect the switching elements S6 and S1 or the input power supply side.

  As described above, in the power conversion device 100A according to the present embodiment, even when an abnormality in which the output voltage rises that causes a short-circuit failure of the switching element occurs in the drive power supply, the influence of the abnormality is prevented from spreading. be able to. For this reason, if power converter 100A is used, a system with high safety and reliability can be constructed compared with the case where conventional power converter 200 is used.

  In addition, since the power conversion device 100A does not have the feedback signal line 25, if an abnormality in which the output voltage of the drive power supply increases occurs, it depends on reasons other than the disconnection of the feedback signal line 25. That is, in the power conversion device 100A, the cause of occurrence of an abnormality in which the output voltage of the drive power source increases is reduced as compared with the conventional power conversion device 200. Also from this point, it can be said that if the power conversion device 100A is used, a system with higher safety and reliability can be constructed compared to the case where the conventional power conversion device 200 is used.

Second Embodiment
FIG. 2 is a circuit diagram showing a configuration of a power conversion device 100B according to the second embodiment of the present invention. The power conversion device 100B of the present embodiment is different from the power conversion device 100A of the first embodiment in the combination of connection between the drive power sources 71 to 73 and the drive circuits 11 to 16.

  In power converter 100B, both ends of secondary winding W21 of drive power supply 71 are connected to drive circuit 11 that drives switching element S1 of the U-phase upper arm, and both ends of secondary winding W22 of drive power supply 71 are connected. Are connected to a drive circuit 13 for driving the switching element S3 of the V-phase upper arm. Further, both ends of the secondary winding W21 of the drive power source 72 are connected to the drive circuit 14 that drives the switching element S4 of the V-phase lower arm, and both ends of the secondary winding W22 of the drive power source 72 are connected to the W phase. It is connected to a drive circuit 16 that drives the switching element S6 of the lower arm. Further, both ends of the secondary winding W21 of the drive power source 73 are connected to the drive circuit 15 that drives the switching element S5 of the W-phase upper arm, and both ends of the secondary winding W22 of the drive power source 73 are connected to the U phase. It is connected to the drive circuit 12 that drives the switching element S2 of the lower arm.

  In the power conversion device 100B, even if an abnormality in which the output voltage of the drive power supply 71 rises and the switching elements S1 and S3 are short-circuited, the switching elements S2 and S4 do not have any abnormality in the drive power supplies 72 and 73. Does not cause a short circuit failure, and the influence of the abnormality of the drive power supply 71 does not spread. Similarly, even if an abnormality in which the output voltage of the drive power supply 72 increases and the switching elements S4 and S6 are short-circuited, if no abnormality occurs in the drive power supplies 71 and 73, the switching elements S3 and S5 are short-circuited. There is no effect, and the influence of the abnormality of the drive power source 72 does not spread. Similarly, even if an abnormality occurs in which the output voltage of the drive power supply 73 increases and the switching elements S2 and S5 are short-circuited, if no abnormality occurs in the drive power supplies 71 and 72, the switching elements S1 and S6 are short-circuited. There is no failure and the influence of the abnormality of the drive power source 73 does not spread.

  Therefore, the same effect as that of the first embodiment can be obtained in this embodiment.

<Third Embodiment>
FIG. 3 is a circuit diagram showing a configuration of a power conversion device 100C according to the third embodiment of the present invention. The power conversion device 100C of this embodiment has a combination of a point having two drive power sources 74 and 75 instead of the three drive power sources 71 to 73 and a connection between the drive power sources 74 to 75 and the drive circuits 11 to 16. Different from the power conversion device 100A of the first embodiment.

  Each of the drive power supplies 74 and 75 has the same configuration. The drive power supplies 74 and 75 differ from the drive power supplies 71 to 73 in that a transformer 26 including three secondary windings W21 to W23 is provided in place of the transformer 21 including two secondary windings W21 and W22. . That is, each of drive power supplies 74 and 75 includes three output units. The primary winding W1 (not shown) of the drive power supplies 74 and 75, the secondary winding W21, the secondary winding W22 and the secondary winding W23 are coupled by a magnetic element such as an iron core or ferrite. In the drive power supplies 74 and 75, the turns ratio between the primary winding W1 and the secondary winding W21, the turns ratio between the primary winding W1 and the secondary winding W22, and the primary winding W1 and the secondary winding. The turn ratio with the line W23 is the same.

  In the power converter 100C, both ends of the secondary winding W21 of the drive power supply 74 are connected to the drive circuit 11 that drives the switching element S1 of the U-phase upper arm, and both ends of the secondary winding W22 of the drive power supply 74 are connected. Is connected to the drive circuit 13 that drives the switching element S3 of the V-phase upper arm, and both ends of the secondary winding W23 of the drive power source 74 are connected to the drive circuit 15 that drives the switching element S5 of the W-phase upper arm. It is connected. Further, both ends of the secondary winding W21 of the drive power source 75 are connected to the drive circuit 12 that drives the switching element S2 of the U-phase lower arm, and both ends of the secondary winding W22 of the drive power source 75 are connected to the V phase. Both ends of the secondary winding W23 of the drive power source 75 are connected to the drive circuit 16 that drives the switching element S6 of the W-phase lower arm. .

  In the power conversion device 100C, even if an abnormality in which the output voltage of the drive power supply 74 increases and the switching elements S1, S3, and S5 are short-circuited, if the abnormality does not occur in the drive power supply 75, the switching elements S2, S4 And S6 does not cause a short circuit failure, and the influence of the abnormality of the drive power supply 74 does not spill over to the switching elements S2, S4 and S6 and the input power supply side. Similarly, even if an abnormality in which the output voltage of the drive power supply 75 increases and the switching elements S2, S4, and S6 are short-circuited, if no abnormality occurs in the drive power supply 74, the switching elements S1, S3, and S5 There is no short circuit failure, and the influence of the abnormality of the drive power supply 75 does not spread to the switching elements S1, S3 and S5 and the input power supply side.

  Therefore, the same effect as that of the first embodiment can be obtained in this embodiment.

<Fourth embodiment>
FIG. 4 is a circuit diagram showing a configuration of a power conversion device 100D according to the fourth embodiment of the present invention. The power conversion device 100D of the present embodiment is different from the power conversion device 100C of the third embodiment in the combination of connections between the drive power supplies 74 to 75 and the drive circuits 11 to 16.

  The connection destinations at both ends of the secondary winding W21 of the drive power supply 74 and the connection destinations at both ends of the secondary winding W23 of the drive power supply 74 are the same as those of the power converter 100C of the third embodiment. In the power converter 100D, both ends of the secondary winding W22 of the drive power source 74 are connected to the drive circuit 14 that drives the switching element S4 of the V-phase lower arm. The connection destinations at both ends of the secondary winding W21 of the drive power supply 75 and the connection destinations at both ends of the secondary winding W23 of the drive power supply 75 are the same as those of the power converter 100C of the third embodiment. In power converter 100D, both ends of secondary winding W22 of drive power supply 75 are connected to drive circuit 13 that drives switching element S3 of the V-phase upper arm.

  In the power conversion device 100D, even if an abnormality in which the output voltage of the drive power supply 74 increases and the switching elements S1, S4, and S5 are short-circuited, if no abnormality occurs in the drive power supply 75, the switching elements S2, S3 And S6 does not cause a short circuit failure, and the influence of the abnormality of the drive power supply 74 does not spread. Similarly, even if an abnormality in which the output voltage of the drive power supply 75 increases and the switching elements S2, S3, and S6 are short-circuited, if no abnormality occurs in the drive power supply 74, the switching elements S1, S4, and S5 There is no short circuit failure, and the influence of the abnormality of the drive power supply 75 does not spread.

  Therefore, the same effect as that of the first embodiment can be obtained in this embodiment.

<Fifth Embodiment>
FIG. 5 is a circuit diagram showing a configuration of a power conversion device 100E according to the fifth embodiment of the present invention. The power conversion device 100E of the present embodiment has a first combination of a point having driving power sources 74, 71 and 76 instead of the driving power sources 71 to 73 and a connection between the driving power sources 74, 71 and 76 and the driving circuits 11 to 16. Different from the power conversion device 100A of the embodiment.

  The drive power supply 74 in the power conversion device 100E is the same as the drive power supply 74 in the third and fourth embodiments. The drive power supply 71 in the power conversion device 100E is the same as the drive power supply 71 of the first and second embodiments. The drive power supply 76 in the power conversion device 100E is different from the drive power supply 71 in that it includes a transformer 27 including one secondary winding W21 instead of the transformer 21. That is, the drive power supply 76 includes one output unit. The primary winding W1 (not shown) and the secondary winding W21 of the drive power source 76 are coupled by a magnetic element such as an iron core or ferrite.

  In the power conversion device 100E, both ends of the secondary winding W21 of the drive power supply 74 are connected to the drive circuit 11 that drives the switching element S1 of the U-phase upper arm, and both ends of the secondary winding W22 of the drive power supply 74 are connected. Is connected to the drive circuit 13 that drives the switching element S3 of the V-phase upper arm, and both ends of the secondary winding W23 of the drive power source 74 are connected to the drive circuit 15 that drives the switching element S5 of the W-phase upper arm. It is connected. Further, both ends of the secondary winding W21 of the drive power supply 71 are connected to the drive circuit 12 that drives the switching element S2 of the U-phase lower arm, and both ends of the secondary winding W22 of the drive power supply 71 are connected to the V-phase. It is connected to the drive circuit 14 that drives the switching element S4 of the lower arm. Further, both ends of the secondary winding W21 of the drive power source 76 are connected to the drive circuit 16 that drives the switching element S6 of the W-phase lower arm.

  In the power conversion device 100E, even if an abnormality in which the output voltage of the drive power supply 74 increases and the switching elements S1, S3, and S5 are short-circuited, if no abnormality occurs in the drive power supplies 71 and 76, the switching element S2 , S4 and S6 do not cause a short circuit failure, and the influence of the abnormality of the drive power supply 74 does not spread to the switching elements S2, S4 and S6 and the input power supply side. Similarly, even if an abnormality in which the output voltage of the drive power supply 71 rises and the switching elements S2 and S4 are short-circuited, the switching elements S1 and S3 are short-circuited if no abnormality occurs in the drive power supply 74. No, the influence of the abnormality of the drive power supply 71 does not affect the switching elements S1 and S3 and the input power supply side. Similarly, even if an abnormality in which the output voltage of the drive power supply 76 increases and the switching element S6 is short-circuited, if the drive power supply 74 is not abnormal, the switching element S5 will not be short-circuited and the drive The influence of the abnormality of the power supply 76 does not affect the switching element S5 or the input power supply side.

  Therefore, the same effect as that of the first embodiment can be obtained in this embodiment.

<Summary>
The power converters 100A to 100E of the first to fifth embodiments have a three-phase output configuration. However, the power converter according to the present invention is not limited to a three-phase output. Hereinafter, a more general aspect of the power conversion device according to the present invention will be described. The power conversion device according to the present invention may be any configuration as long as it satisfies the conditions 1 and 2 shown below, and may have any specific configuration. This is because the effects of the present invention can be obtained by satisfying Condition 1 and Condition 2.

Condition 1 is a condition regarding the number of drive power supplies and the number of output portions of the drive power supplies.
(Condition 1): The number of drive power supplies is two or more and less than the number of drive circuits (in other words, the number of switching elements). The number of output units per drive power supply is equal to or less than the number of phases (in other words, the number of switching element modules). The total of the output units of all the drive power supplies is equal to or less than the number of drive circuits (in other words, the number of switching elements). At least one drive power source including a plurality of output units is provided.

Condition 2 is a connection condition between the drive power supply and the drive circuit.
(Condition 2): In any phase (that is, the switching element module), a driving power supply that is different from the driving power supply that supplies power to the driving circuit that drives the switching element on one side of the switching element module Power is supplied to a drive circuit that drives the switching element on the other side.

  That is, in the power conversion device according to the present invention, the upper arm including the switching element and the lower arm including the switching element are connected in series between the input power lines, and one phase is formed with the connection point of the upper arm and the lower arm as the output terminal. In a power converter configured and having a plurality of upper arms and lower arms, the power converter includes a plurality of drive circuits provided for each switching element of the upper and lower arms and driving the switching elements of the upper and lower arms, and a plurality of driving power sources. At least one of the plurality of drive power supplies includes a plurality of output units that output electric power, and in any phase, the drive circuit that drives the switching element on one side of the upper and lower arms is provided on one side. A drive that is separate from the drive power source to which the output unit connected to the drive circuit that drives the other switching element connected in series to the switching element belongs. It is intended to be connected to the output of the power supply.

  In the power conversion device according to the present invention, even if an abnormality in which the output voltage rises that causes a short-circuit failure of the switching element occurs in the drive power supply, the influence of the abnormality does not spread. In the power conversion device according to the present invention, at least one of the plurality of drive power supplies includes a plurality of output units. For this reason, in this power converter device, the number of drive power supplies becomes less than the number of drive circuits, and the influence of the abnormality of the drive power supply can be avoided while suppressing the cost related to the drive power supply.

  The power conversion devices 100A and 100B according to the first and second embodiments are an example in which a drive power source including two output units is provided for the number of phases. In power converters 100A and 100B, only a 1-input 2-output transformer is used as a transformer for realizing the output unit. Since this transformer can be obtained at low cost, according to the aspects of the first and second embodiments, the power conversion devices 100A and 100B can be configured at low cost. Also, a 1-input 2-output transformer has better regulation than a 2-output transformer. For this reason, according to the drive power supply of the first and second embodiments, a stable output can be supplied to the drive circuit as compared with a drive power supply using a transformer having a larger number of outputs than two.

  In the power conversion device 100B of the second embodiment, one output unit of each of the plurality of drive power supplies is connected to a drive circuit that drives one of the switching elements of the upper and lower arms in any phase. The other output section of each of the drive power supplies drives one of the switching elements of the upper and lower arms in another phase different from the phase including the switching element driven by the drive circuit to which the one output section is connected. Connected to the drive circuit. On the other hand, in the power conversion device 100A according to the first embodiment, one output unit of each of the plurality of drive power supplies is connected to a drive circuit that drives the switching element on one side of the upper and lower arms in any phase. The other output part of each drive power supply drives the switching element on the other side of the upper and lower arms in another phase different from the phase including the switching element driven by the drive circuit to which the one output part is connected Connected to. In the power conversion device 100A of the first embodiment, since the connection between the drive power supply and the drive circuit is regular compared to the power conversion device 100B of the second embodiment, the wiring between the drive power supply and the drive circuit is limited. It can be expected that the symmetry component is increased or the wiring length is shortened so that the inductance component due to the wiring is reduced, resulting in low noise and low loss.

  The power conversion devices 100C and 100D according to the third and fourth embodiments are examples in which two drive power supplies including the output units corresponding to the number of phases are included. According to the aspects of the third and fourth embodiments, the total number of transformers that realize the output unit can be reduced to two. For this reason, according to the aspect of 3rd and 4th embodiment, compared with other embodiment which requires many transformers rather than two, it becomes possible to make the space required for installing a transformer small.

  In the power conversion device 100D of the fourth embodiment, each output unit of the drive power supply is connected to a drive circuit of a different phase. On the other hand, in the power conversion device 100C of the third embodiment, each of the output units of one drive power supply is connected to a drive circuit that drives a switching element on one side of the upper and lower arms of each phase, and the output of the other drive power supply Each of the units is connected to a drive circuit that drives the switching element on the other side of the upper and lower arms of each phase. In the power conversion device 100C of the third embodiment, since the connection between the drive power supply and the drive circuit is regular compared to the power conversion device 100D of the fourth embodiment, the same as the power conversion device 100A of the first embodiment. In addition, low noise and low loss can be expected.

  The power conversion device 100E according to the fifth embodiment is an example of a configuration in which a plurality of drive power sources, which are different from the other drive power sources among the plurality of drive power sources, are included in the plurality of drive power sources. Thus, each of the plurality of drive power supplies may have a different number of output units.

  Further, since the power conversion device 100E of the fifth embodiment is an example of three-phase output, one drive power source including three output units, one drive power source including two output units, One driving power source including one output unit was included. When the fifth embodiment is expanded to increase the number of phases to more than three phases, for example, the power conversion device includes one first drive power source that includes the number of phases of the output unit and the number of phases of the output unit. One or a plurality of second drive power supplies including a small number and one or a plurality of third drive power supplies including a number of output units smaller than the number of output units included in the second drive power supply Each of the output units of the first drive power supply is connected to a drive circuit that drives a switching element on one side of the upper and lower arms of each phase, and the output unit of the second drive power supply and the output unit of the third drive power supply May be configured to be connected to a drive circuit that drives the switching element on the other side of the upper and lower arms of each phase.

<Other embodiments>
As mentioned above, although each embodiment of this invention was described, other embodiment can be considered to this invention. For example:

(1) The switching elements S1 to S6 of the power conversion devices 100A to 100E of the embodiments are not limited to IGBTs. For example, the switching elements S1 to S6 may be a GTO (Gate Turn-Off Thyristor), a MOSFET, or the like.

(2) In the power converters 100A to 100E of the respective embodiments, the secondary winding for control having both ends connected to the control means 24 is provided on the secondary side of the transformers 21, 26 and 27 of the drive power sources 71 to 76. May be. The control secondary winding, the primary winding W1, and the secondary windings W21 to W23 are coupled by a magnetic element. By supplying the output voltage of the secondary winding for control to the control means 24, the outputs of the secondary windings W21 to W23 can be controlled more accurately.

(3) The drive power supplies 71 to 76 of each embodiment may be a flyback converter as long as power is sent to the secondary windings W21 to W23 via the transformers 21, 26 and 27. Alternatively, a forward converter may be used.

(4) In the power converters 100A to 100E of the embodiments, power is supplied from the DC power supply 8 to the drive power supplies 71 to 76. However, in the power conversion device according to the present invention, power may be supplied to the drive power supplies 71 to 76 from a power supply different from the DC power supply 8. For example, when the power conversion device according to the present invention is mounted on an electric vehicle or a hybrid vehicle, a high-voltage lithium ion battery such as the electric vehicle is used as the DC power supply 8 and a low-voltage lead-acid battery is supplied to the drive power supplies 71 to 76. It may be used as a direct current power source.

(5) The power conversion devices 100A to 100E of the embodiments are power conversion devices that convert the DC power of the DC power supply 8 into three-phase AC power. However, the power conversion device according to the present invention may include, for example, a PWM (Pulse Width Modulation) rectifier that converts AC power into DC power and has the technical features of this specification.

  100A, 100B, 100C, 100D, 100E, 200 ... power converter, 1, 2, 3 ... switching element module, 8 ... DC power supply, 11, 12, 13, 14, 15, 16 ... drive circuit, 21, 26 DESCRIPTION OF SYMBOLS 27 ... Transformer, 22 ... Capacitor, 23 ... Transistor, 24 ... Control means, 25 ... Feedback signal line, 51 ... Rectifier circuit, 52 ... Capacitor, 53, 54, 55, 57 ... Fuse, 56 ... AC power supply, 58 ... Battery 71, 72, 73, 74, 75, 76, 41, 42, 43... Drive power supply, S1, S2, S3, S4, S5, S6... Switching element, D1, D2, D3, D4, D5, D6. Diode, W1 ... primary winding, W21, W22, W23 ... secondary winding, R1, R2 ... resistance.

Claims (7)

An upper arm including a switching element and a lower arm including a switching element are connected in series between input power supply lines, and one phase is configured with a connection point of the upper arm and the lower arm as an output end, and the upper arm and the In the power converter having a lower arm for a plurality of phases,
A plurality of drive circuits provided for each switching element of the upper and lower arms, and driving the switching elements of the upper and lower arms;
A plurality of drive power supplies,
At least one drive power supply among the plurality of drive power supplies includes a plurality of output units that output power,
In any phase, the drive circuit for driving the switching element on one side of the upper and lower arms belongs to the output unit connected to the drive circuit for driving the other switching element connected in series to the one switching element. A power conversion device, wherein the power conversion device is connected to an output section of a drive power supply that is separate from the drive power supply. As the plurality of drive power supplies, the drive power supplies including the two output units are included in the number of phases,
One output section of each of the plurality of drive power supplies is connected to a drive circuit that drives one of the switching elements of the upper and lower arms in any phase,
The other output part of each of the plurality of drive power supplies is one of the switching elements of the upper and lower arms in another phase different from the phase including the switching element driven by the drive circuit to which the one output part is connected The power converter according to claim 1, wherein the power converter is connected to a drive circuit that drives As the plurality of drive power supplies, the drive power supplies including the two output units are included in the number of phases,
One output portion of each of the plurality of drive power supplies is connected to a drive circuit that drives a switching element on one side of the upper and lower arms in any phase,
The other output part of each of the plurality of drive power supplies includes a switching element on the other side of the upper and lower arms in another phase different from the phase including the switching element driven by the drive circuit to which the one output part is connected. The power conversion device according to claim 1, wherein the power conversion device is connected to a driving circuit to be driven. As the plurality of drive power supplies, there are two drive power supplies including the number of phases of the output unit,
Each of the output part of the said drive power supply is connected to the drive circuit of a different phase. The power converter device of Claim 1 characterized by the above-mentioned. As the plurality of drive power supplies, there are two drive power supplies including the number of phases of the output unit,
Each output part of one drive power supply is connected to a drive circuit that drives a switching element on one side of the upper and lower arms of each phase,
Each of the output parts of the other drive power supply is connected to the drive circuit which drives the switching element of the other side of the upper-lower arm of each phase. The power converter device of Claim 1 characterized by the above-mentioned. The power converter according to claim 1, wherein the plurality of drive power supplies include a drive power supply having a different number of the output units from another drive power supply among the plurality of drive power supplies. . As the plurality of drive power supplies,
One first drive power supply including the output unit by the number of phases;
One or a plurality of second drive power supplies including the output unit less than the number of phases;
One or a plurality of third drive power supplies including the output unit by a number smaller than the number of output units included in the second drive power supply,
Each of the output units of the first drive power supply is connected to a drive circuit that drives a switching element on one side of the upper and lower arms of each phase,
The output section of the second drive power supply and the output section of the third drive power supply are connected to a drive circuit that drives the switching element on the other side of the upper and lower arms of each phase. The power converter described.

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