Power conversion device and vehicle

Abstract

The present invention provides a power conversion device and a vehicle having the power conversion device, wherein the power conversion device restores the output signal of the gate drive circuit to a normal state when the gate drive circuit malfunctions due to static electricity. When a short circuit is detected between a positive-side DC bus (32p) and a negative-side DC bus (32n), a gate signal control unit (50) of the power conversion device (20) sends a first gate signal that temporarily turns on a positive-side switch element (switch element (30a, 30c, 30e)) and then turns it off to a positive-side gate drive circuit (gate drive circuit (40a, 40c, 40e)), and sends a second gate signal that temporarily turns on a negative-side switch element (switch element (30b, 30d, 30f)) and then turns it off to a negative-side gate drive circuit (gate drive circuit (40b, 40d, 40f)).

Description

Technical Field

[0001] The present invention relates to a power conversion device for turning on / off a switching element by a gate drive circuit and a vehicle having the power conversion device. Background Art

[0002] In the power conversion device, two switching elements are connected in series, and the two switching elements connected in series are inserted between a positive-side DC bus and a negative-side DC bus. An output node is connected between the two switching elements connected in series.

[0003] In a power conversion device, a short-circuit fault (on-stuck) in which a switching element is fixed in an on state may occur. In addition, if a short-circuit fault occurs in both the switching element between the positive-side DC bus and the output node (hereinafter referred to as the positive-side switching element) and the switching element between the negative-side DC bus and the output node (hereinafter referred to as the negative-side switching element), or if a short-circuit fault occurs in one of the positive-side switching element and the negative-side switching element while the other switching element is "on", a short circuit may occur between the DC buses.

[0004] Therefore, there is a disclosed technology for suppressing adverse effects such as damage to various devices connected to a power conversion device when a short-circuit failure occurs in a switching element and a DC bus is short-circuited (for example, Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2010-98790 Summary of the invention

[0008] Technical issues

[0009] However, a gate drive circuit and a gate signal control unit are provided in the power conversion device. The gate drive circuit is provided for each switching element. The gate signal control unit sends a gate signal indicating that the switching element is turned on or off to the gate drive circuit. The gate drive circuit turns the switching element on or off according to the gate signal.

[0010] In addition, in the gate drive circuit, an isolation transformer is sometimes provided to insulate the gate signal control unit side from the switching element side. The isolation transformer does not transmit the DC portion of the primary side to the secondary side, but only transmits the rising edge and falling edge of the pulsed gate signal to the secondary side. Therefore, in the gate drive circuit provided with an isolation transformer, a latch circuit is provided on the secondary side of the isolation transformer. If the latch circuit receives a rising edge, it keeps the output in a high level state (for example, an "ON" state), and if it receives a falling edge, it keeps the output in a low level state (for example, an "OFF" state).

[0011] Here, for example, static electricity may be applied to the gate drive circuit when a person touches the power converter, etc. In this case, the gate drive circuit may malfunction in a manner opposite to a normal gate signal, and the latch circuit may continue to output an output signal that turns the switch element "on".

[0012] For example, if one of the positive-side switching element and the negative-side switching element continues to be “ON” due to a malfunction caused by static electricity, when the other switching element is “ON”, a short circuit occurs between the DC buses.

[0013] When the switching element is turned “on” due to static electricity, since the switching element itself is not faulty, if the output signal of the gate drive circuit can be restored to a normal state, the switching element can be restored to an “off” state.

[0014] However, when the gate signal control unit detects a short circuit between the DC buses, it cannot distinguish whether the short circuit is caused by a short circuit failure of the switching element or a malfunction caused by static electricity. Therefore, when the gate signal control unit detects a short circuit between the DC buses, it treats it as a failure of the power conversion device regardless of the actual cause of the short circuit. As a result, sometimes even if the abnormality of the switching element can be restored, the power conversion device is replaced and repaired in a wasteful manner.

[0015] Therefore, an object of the present invention is to provide a power conversion device and a vehicle capable of restoring an output signal of a gate drive circuit to a normal state when the gate drive circuit malfunctions due to static electricity.

[0016] Technical Solution

[0017] In order to solve the above-mentioned problems, the power conversion device of the present invention comprises: a positive-side switching element, which is arranged between the positive-side DC bus and the output node; a negative-side switching element, which is arranged between the negative-side DC bus and the output node; a positive-side gate driving circuit, which turns on and off the positive-side switching element; a negative-side gate driving circuit, which turns on and off the negative-side switching element; and a gate signal control unit, which sends a gate signal indicating the turning on and off of the positive-side switching element to the positive-side gate driving circuit, and sends a gate signal indicating the turning on and off of the negative-side switching element to the negative-side gate driving circuit, and when the gate signal control unit detects a short circuit between the positive-side DC bus and the negative-side DC bus, the first gate signal that temporarily turns on the positive-side switching element and then turns it off is sent to the positive-side gate driving circuit, and the second gate signal that temporarily turns on the negative-side switching element and then turns it off is sent to the negative-side gate driving circuit.

[0018] In addition, the gate signal control unit may transmit the first gate signal and the second gate signal in such a manner that the transmission timings are different.

[0019] In addition, the gate signal control unit may transmit the first gate signal and the second gate signal after a predetermined time has passed since the transmission of the other one.

[0020] In addition, the gate signal control unit may repeat the transmission of the first gate signal and the transmission of the second gate signal alternately a plurality of times.

[0021] In addition, the gate signal control unit can determine that a short circuit fault has occurred in the negative side switching element when a short circuit is detected again between the positive side DC bus and the negative side DC bus when the first gate signal is sent for the second time or later, and can determine that a short circuit fault has occurred in the positive side switching element when a short circuit is detected again between the positive side DC bus and the negative side DC bus when the second gate signal is sent for the second time or later.

[0022] In addition, when the gate signal control unit detects a short circuit between the positive side DC bus and the negative side DC bus, and the electric generator connected to the output node is already rotating, it does not send the first gate signal and the second gate signal, but regards that a short circuit fault has occurred in the positive side switching element or the negative side switching element. Moreover, when the gate signal control unit detects a short circuit between the positive side DC bus and the negative side DC bus, and the electric generator is already stopped, the first gate signal and the second gate signal are sent, so that if the short circuit is caused by a malfunction of one or both of the positive side gate drive circuit and the negative side gate drive circuit, the short circuit can be recovered from.

[0023] The vehicle of the present invention comprises: an electric generator that generates electricity based on the drive of an engine; a power conversion device that transmits and receives electric power to and from the electric generator; and a vehicle control unit that controls the power conversion device, wherein the power conversion device comprises: a positive-side switching element that is arranged between a positive-side DC bus and an output node; a negative-side switching element that is arranged between a negative-side DC bus and an output node; a positive-side gate drive circuit that turns on and off the positive-side switching element; a negative-side gate drive circuit that turns on and off the negative-side switching element; and a gate signal control unit that instructs the positive-side switching element The gate signal for turning on and off is sent to the positive side gate drive circuit, and the gate signal for indicating the turning on and off of the negative side switching element is sent to the negative side gate drive circuit. When the gate signal control unit detects a short circuit between the positive side DC bus and the negative side DC bus, the gate signal control unit sends a first gate signal that temporarily turns on the positive side switching element and then turns it off to the positive side gate drive circuit, and sends a second gate signal that temporarily turns on the negative side switching element and then turns it off to the negative side gate drive circuit. When one or both of the trunk door and the rear door are opened, the vehicle control unit allows the power conversion device to stop the electric generator.

[0024] Technical Effects

[0025] According to the present invention, when the gate driving circuit malfunctions due to static electricity, the output signal of the gate driving circuit can be restored to a normal state. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram showing the configuration of a vehicle according to the present embodiment.

[0027] Figure 2 It is a schematic diagram showing the configuration of the power conversion device according to the present embodiment.

[0028] Figure 3 Schematic diagram showing the configuration of a gate drive circuit.

[0029] Figure 4 This is a timing chart for explaining the operation of the power conversion device when static electricity is applied.

[0030] Figure 5 This is a timing chart for explaining the operation of the power conversion device when a short-circuit failure occurs in a switching element.

[0031] Figure 6 This is a flowchart for explaining the operation of the gate signal control unit of the power conversion device.

[0032] Figure 7 This is a flowchart for explaining the operation of the vehicle control unit when the vehicle is parked.

[0033] Explanation of symbols

[0034] 1 Vehicle

[0035] 14 Electric generator

[0036] 20 Power conversion device

[0037] 30, 30a, 30b, 30c, 30d, 30e, 30f switch element

[0038] 32p positive side DC bus

[0039] 32n Negative side DC bus

[0040] 36u, 36v, 36w output nodes

[0041] 40, 40a, 40b, 40c, 40d, 40e, 40f gate drive circuit

[0042] 50 Gate signal control unit DETAILED DESCRIPTION

[0043] Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific values ​​shown in the embodiment are only examples for facilitating the understanding of the invention, and are not intended to limit the present invention unless otherwise specified. It should be noted that in this specification and the accompanying drawings, the same symbols are used for elements having substantially the same functions and structures, thereby omitting repeated descriptions, and elements that are not directly related to the present invention are omitted from illustration.

[0044] Figure 1 1 is a schematic diagram showing a configuration of a vehicle 1 according to the present embodiment. The vehicle 1 is, for example, a series-parallel (power-split) hybrid vehicle (hybrid electric vehicle).

[0045] The vehicle 1 includes an engine 10 , a power split mechanism 12 , a first motor generator 14 a , a second motor generator 14 b , a speed reduction mechanism 16 , drive wheels 18 , a power conversion device 20 a , a power conversion device 20 b , a battery 22 , and a vehicle control unit 24 .

[0046] The engine 10 is, for example, a gasoline engine or a diesel engine. The engine 10 is connected to a power split mechanism 12. The power split mechanism 12 is configured to include, for example, a planetary gear mechanism. In addition to the engine 10, the power split mechanism 12 is also connected to a first motor generator (first MG) 14a and a speed reduction mechanism 16.

[0047] The speed reduction mechanism 16 is configured to include a plurality of gear mechanisms. The speed reduction mechanism 16 is connected to the second motor generator (second MG) 14b. In addition, the speed reduction mechanism 16 is connected to the drive wheel 18 via a differential gear or the like. The power distribution mechanism 12 distributes the power of the engine 10 into the power for rotating the first motor generator 14a and the power for rotating the drive wheel 18.

[0048] The first motor generator 14a is connected to the battery 22 via the power conversion device 20a. The first motor generator 14a mainly functions as a generator according to the drive of the engine 10. The power conversion device 20a converts the AC power generated by the first motor generator 14a into DC power and supplies it to the battery 22. It should be noted that the first motor generator 14a may also function as a motor.

[0049] The second motor generator 14b is connected to the battery 22 via the power conversion device 20b. When the vehicle 1 is accelerating, the power conversion device 20b converts the direct current supplied from the battery 22 into a desired alternating current and supplies it to the second motor generator 14b. At this time, the second motor generator 14b mainly functions as a motor and drives the vehicle 1 according to the alternating current supplied from the power conversion device 20b. It should be noted that when the vehicle 1 is decelerating, the second motor generator 14b can be made to function as a generator.

[0050] The vehicle control unit 24 is composed of a semiconductor integrated circuit including a central processing unit, a ROM storing programs, and a RAM as a work area. The vehicle control unit 24 mainly performs control related to the driving of the vehicle 1. For example, the vehicle control unit 24 controls the engine 10 based on the detection results of various sensors not shown. In addition, the vehicle control unit 24 controls the first motor generator 14a and the second motor generator 14b by controlling the power conversion devices 20a and 20b.

[0051] The power conversion devices 20a and 20b are provided, for example, below the rear seats and / or below the trunk of the vehicle 1. The power conversion devices 20a and 20b are hereinafter collectively referred to as the power conversion device 20. The first motor generator 14a and the second motor generator 14b are collectively referred to as the motor generator (MG) 14.

[0052] Figure 21 is a schematic diagram showing the structure of the power conversion device 20 of the present embodiment. The power conversion device 20 is configured to include switching elements 30a, 30b, 30c, 30d, 30e, 30f; a positive-side DC bus 32p; a negative-side DC bus 32n; freewheeling diodes 34a, 34b, 34c, 34d, 34e, 34f; a capacitor 38; gate drive circuits 40a, 40b, 40c, 40d, 40e, 40f; and a gate signal control unit 50.

[0053] The switching elements 30a, 30b, 30c, 30d, 30e, and 30f are, for example, IGBTs (Insulated Gate Bipolar Transistors). The collector C of the switching element 30a is connected to the positive-side DC bus 32p. The emitter E of the switching element 30a is connected to the collector C of the switching element 30b. The emitter E of the switching element 30b is connected to the negative-side DC bus 32n.

[0054] The collector C of the switching element 30c is connected to the positive-side DC bus 32p. The emitter E of the switching element 30c is connected to the collector C of the switching element 30d. The emitter E of the switching element 30d is connected to the negative-side DC bus 32n.

[0055] The collector C of the switching element 30e is connected to the positive-side DC bus 32p. The emitter E of the switching element 30e is connected to the collector C of the switching element 30f. The emitter E of the switching element 30f is connected to the negative-side DC bus 32n.

[0056] That is, two switching elements 30a and 30b connected in series, two switching elements 30c and 30d connected in series, and two switching elements 30e and 30f connected in series are inserted in parallel between the positive-side DC bus 32p and the negative-side DC bus 32n.

[0057] Hereinafter, the switching elements 30a, 30b, 30c, 30d, 30e, and 30f are sometimes collectively referred to as the switching elements 30. In addition, in the switching elements 30, the switching elements 30a, 30c, and 30e are sometimes referred to as positive-side switching elements, and the switching elements 30b, 30d, and 30f are sometimes referred to as negative-side switching elements. In addition, the area between the positive-side DC bus 32p and the negative-side DC bus 32n is sometimes referred to as between the DC buses.

[0058] The cathode K of the flywheel diode 34a is connected to the collector C of the switching element 30a, and the anode A of the flywheel diode 34a is connected to the emitter E of the switching element 30a. That is, the flywheel diode 34a is connected in reverse parallel to the switching element 30a. Similarly, the flywheel diodes 34b, 34c, 34d, 34e, and 34f are connected in reverse parallel to the switching elements 30b, 30c, 30d, 30e, and 30f, respectively.

[0059] The connection node between the emitter E of the switching element 30a and the collector C of the switching element 30b functions as the output node 36u of the U phase. Similarly, the connection node between the emitter E of the switching element 30c and the collector C of the switching element 30d functions as the output node 36v of the V phase, and the connection node between the emitter E of the switching element 30e and the collector C of the switching element 30f functions as the output node 36w of the W phase.

[0060] The positive-side DC bus 32p is connected to the positive electrode of the battery 22, and the negative-side DC bus 32n is connected to the negative electrode of the battery 22. A capacitor 38 is inserted between the DC buses. The capacitor 38 smoothes the voltage between the DC buses.

[0061] The gate drive circuit 40a is connected to the gate G of the switching element 30a, and turns the switching element 30a on and off. Similarly, the gate drive circuit 40b is connected to the gate G of the switching element 30b, and turns the switching element 30b on and off. The gate drive circuit 40c is connected to the gate G of the switching element 30c, and turns the switching element 30c on and off. The gate drive circuit 40d is connected to the gate G of the switching element 30d, and turns the switching element 30d on and off. The gate drive circuit 40e is connected to the gate G of the switching element 30e, and turns the switching element 30e on and off. The gate drive circuit 40f is connected to the gate G of the switching element 30f, and turns the switching element 30f on and off.

[0062] In addition, the gate drive circuits 40a and 40b detect whether the DC bus is short-circuited through the U-phase switching elements 30a and 30b, and send a short-circuit signal indicating the presence of the short-circuit to the gate signal control unit 50. The gate drive circuits 40c and 40d detect whether the DC bus is short-circuited through the V-phase switching elements 30c and 30d, and send a short-circuit signal indicating the presence of the short-circuit to the gate signal control unit 50. The gate drive circuits 40e and 40f detect whether the DC bus is short-circuited through the W-phase switching elements 30e and 30f, and send a short-circuit signal indicating the presence of the short-circuit to the gate signal control unit 50.

[0063] Hereinafter, the gate drive circuits 40a, 40b, 40c, 40d, 40e, and 40f are sometimes collectively referred to as the gate drive circuit 40. In addition, in the gate drive circuit 40, the gate drive circuits 40a, 40c, and 40e are sometimes referred to as positive-side gate drive circuits, and the gate drive circuits 40b, 40d, and 40f are sometimes referred to as negative-side gate drive circuits.

[0064] The gate signal control unit 50 is composed of a semiconductor integrated circuit including a central processing unit, a ROM storing programs, and a RAM as a work area. The gate signal control unit 50 generates a gate signal for instructing the switching element 30 to turn on and off under the control of the vehicle control unit 24, and sends the generated gate signal to the gate drive circuit 40. The gate signal is, for example, a pulse signal.

[0065] The gate signal control unit 50 receives a short circuit signal from the gate drive circuit 40. If the short circuit signal is OFF, it indicates that there is no short circuit between the DC buses, and if the short circuit signal is ON, it indicates that there is a short circuit between the DC buses.

[0066] Figure 3 2 is a schematic diagram showing the configuration of the gate drive circuit 40. The gate drive circuit 40 includes an isolation transformer 60, a latch circuit 62, and a short-circuit detection unit 64.

[0067] The primary side of the isolation transformer 60 is connected to the gate signal control unit 50 , and the secondary side of the isolation transformer 60 is connected to the latch circuit 62 . The latch circuit 62 is connected to the switching element 30 .

[0068] The isolation transformer 60 insulates the primary side from the secondary side. In addition, the isolation transformer 60 does not transmit the DC portion of the primary side to the secondary side, but transmits only the rising and falling edges of the pulsed gate signal to the secondary side.

[0069] The latch circuit 62 maintains the output in a high level state (e.g., ON state) when receiving a rising edge, and maintains the output in a low level state (e.g., OFF state) when receiving a falling edge. Thus, the latch circuit 62 outputs a pulsed output signal based on the received rising edge and falling edge to the switching element 30.

[0070] The short circuit detection unit 64 detects a short circuit between the DC buses through the switching element 30 by determining whether the current of the switching element 30 is an overcurrent. If the short circuit is detected, the short circuit detection unit 64 continuously sends a short circuit signal "yes" to the gate signal control unit 50 for a predetermined time after the short circuit is detected.

[0071] Then, after a predetermined time has passed, the short-circuit detection unit 64 changes the short-circuit signal from "yes" to "no", and continues to send the short-circuit signal "no" to the gate signal control unit 50 until the next short circuit is detected. Thus, since the short-circuit detection unit 64 continues to send the short-circuit signal "yes" for a predetermined time, the gate signal control unit 50 can receive the short-circuit signal "yes" more reliably.

[0072] Furthermore, when the short-circuit detection unit 64 detects a short-circuit, it transmits a forced signal to the switching element 30 for forcibly turning off the switching element 30 .

[0073] Here, the power conversion device 20 is housed in a metal housing together with, for example, a battery 22 and / or a DC / DC converter, etc. The housing is provided, for example, below the trunk of the vehicle 1. Although the housing is provided below the trunk in a manner covered with a non-metallic material such as plastic, a portion of the housing (metal portion) is exposed due to the structure.

[0074] For example, when a person opens the trunk door of the vehicle 1 and reaches into the trunk, the person may touch the exposed metal portion of the housing that houses the power conversion device 20. If the metal portion is touched by a person, static electricity may be applied to the housing and transferred to the gate drive circuit 40 of the power conversion device 20 through the housing.

[0075] In this case, the gate drive circuit 40 may erroneously operate in a manner opposite to a normal gate signal, and the latch circuit 62 may continue to output an output signal for turning the switching element 30 “ON”.

[0076] For example, if one of the positive-side switching element and the negative-side switching element continues to be “ON” due to a malfunction caused by static electricity, when the other switching element 30 is “ON”, a short circuit occurs between the DC buses.

[0077] In the case of malfunction due to static electricity, since the switch element 30 itself is not faulty, if the output signal of the gate drive circuit 40 can be restored to a normal state, the switch element 30 can be restored to the "off" state.

[0078] Therefore, when the short circuit between the DC buses is detected, the gate signal control unit 50 sends a first gate signal that temporarily turns on the positive side switch element and then turns it off to the positive side gate drive circuit, and sends a second gate signal that temporarily turns on the negative side switch element and then turns it off to the negative side gate drive circuit. In the power conversion device 20, the output signal of the gate drive circuit 40 is restored to a normal state by using the falling edge of the first gate signal and the falling edge of the second gate signal.

[0079] Figure 4 This is a timing chart for explaining the operation of the power conversion device 20 when static electricity is applied. Figure 4 The short-circuit signal shown shows a logical OR of the short-circuit signals sent from the respective gate drive circuits 40 .

[0080] For example, at time T10, the gate signal control unit 50 sends a gate signal "YES" to the gate drive circuit 40b on the negative side of the U phase, and sends a gate signal "NO" to the other gate drive circuits 40a, 40c, 40d, 40e, 40f.

[0081] Assuming that at time T11 later than time T10, as indicated by a dot-dashed circle mark A1, the output signal of the gate drive circuit 40a on the positive side of the U phase, the output signal of the gate drive circuit 40d on the negative side of the V phase, and the output signal of the gate drive circuit 40e on the positive side of the W phase become "yes" respectively due to static electricity, which is opposite to the gate signal. As a result, the switch element 30a on the positive side of the U phase, the switch element 30d on the negative side of the V phase, and the switch element 30e on the positive side of the W phase become "on".

[0082] At time T11, since the switch element 30b on the negative side of the U phase is in the "on" state, the DC bus is short-circuited by the switch elements 30a and 30b of the U phase. At this time, the gate drive circuits 40a and 40b of the U phase set the short-circuit signal to "yes" and send it to the gate signal control unit 50. The sending of the short-circuit signal "yes" is maintained for a predetermined time (for example, until time T14).

[0083] In addition, at time T12 later than time T11, the gate drive circuits 40a and 40b of the U phase send a forced signal to the switch elements 30a and 30b of the U phase to turn off the switch elements 30a and 30b. The sending of the forced signal is the same as the sending of the short-circuit signal "yes", and is maintained for a predetermined time (for example, until time T14). As a result, the switch element 30a corresponding to the gate drive circuit 40a on the positive side of the U phase that malfunctioned due to static electricity is restored to the "off" state.

[0084] At time T13 later than time T12, the gate signal control unit 50, which has received the short-circuit signal "Yes", sets the gate signal to "No" to the gate drive circuits 40a and 40b of the U phase that are the transmission sources of the short-circuit signal "Yes".

[0085] In addition, at time T11, since the switch element 30c on the positive side of the V phase is in the "off" state, no short circuit occurs through the V phase. At this time, the gate drive circuit 40d on the negative side of the V phase to which static electricity is applied continues to output the output signal "yes" due to the latch circuit 62. Therefore, the switch element 30d is maintained in the "on" state.

[0086] In addition, at time T11, since the switch element 30f on the negative side of the W phase is in the "off" state, no short circuit occurs through the W phase. At this time, the gate drive circuit 40e on the positive side of the W phase to which static electricity is applied continues to output the output signal "yes" due to the latch circuit 62. Therefore, the switch element 30e is maintained in the "on" state.

[0087] At time T14 later than time T13 , a predetermined time has elapsed, and therefore the gate drive circuits 40 a and 40 b of the U phase set the short-circuit signal to “No”.

[0088] At time T15 later than time T14, the gate signal control unit 50 sends a gate signal "yes" to the gate drive circuit 40a on the positive side of the U phase, the gate drive circuit 40c on the positive side of the V phase, and the gate drive circuit 40e on the positive side of the W phase. Then, at time T16 shortly after time T15, the gate signal control unit 50 sends a gate signal "no" to the gate drive circuit 40a on the positive side of the U phase, the gate drive circuit 40c on the positive side of the V phase, and the gate drive circuit 40e on the positive side of the W phase. That is, the gate signal control unit 50 sends the first gate signal from time T15 to time T16.

[0089] Here, the gate drive circuit 40 does not receive the gate signal during the period of sending the short-circuit signal "Yes", but sends a forced signal. Therefore, in the power conversion device 20, the time interval from the sending of the short-circuit signal "Yes" (time T11) to the sending of the first gate signal (time T15) is set to be longer than the sending duration of the short-circuit signal "Yes".

[0090] Thus, even if the short-circuit signal becomes “Yes”, the subsequent first gate signal reaches the gate drive circuit 40 after the short-circuit signal becomes “No”. Therefore, the gate drive circuit 40 can appropriately receive the first gate signal.

[0091] At time T15, since the switch element 30d on the negative side of the V phase is in the "on" state due to the influence of static electricity, the DC bus is short-circuited through the switch elements 30c and 30d of the V phase. At this time, the gate drive circuits 40c and 40d of the V phase set the short-circuit signal to "yes" and send it to the gate signal control unit 50. The sending of the short-circuit signal "yes" is maintained for a predetermined time (for example, until time T17).

[0092] In addition, at time T16, the gate drive circuits 40c and 40d of the V phase send a forced signal to the switch elements 30c and 30d of the V phase to turn off the switch elements 30c and 30d. The sending of the forced signal is similar to the sending of the short-circuit signal "yes", and is maintained for a predetermined time (for example, until time T17). As a result, the switch element 30d corresponding to the gate drive circuit 40d on the negative side of the V phase that malfunctioned due to static electricity is restored to the "off" state.

[0093] At time T15, since the switching element 30f on the negative side of the W phase is in the "off" state, no short circuit occurs through the W phase. Therefore, at time T15, the gate drive circuit 40e on the positive side of the W phase continues to output the output signal "Yes".

[0094] Then, at time T16, since the gate signal sent to the gate drive circuit 40e on the positive side of the W phase changes from "yes" to "no", the gate drive circuit 40e on the positive side of the W phase receives a falling edge. As a result, the output of the latch circuit 62 on the positive side of the W phase switches from a high level state to a low level state, and as shown by the circle mark A2 of the single-dot chain line, the output signal of the gate drive circuit 40e on the positive side of the W phase changes to "no". As a result, the switching element 30e corresponding to the gate drive circuit 40e on the positive side of the W phase that malfunctioned due to static electricity returns to the "off" state.

[0095] At time T17 later than time T16, since a predetermined time has elapsed, the gate drive circuits 40c and 40d of the V phase set the short-circuit signal to "No".

[0096] At time T18, which is later than time T17 and a predetermined time after the transmission of the first gate signal, the gate signal control unit 50 transmits a gate signal "Yes" to the gate drive circuit 40b on the negative side of the U phase, the gate drive circuit 40d on the negative side of the V phase, and the gate drive circuit 40f on the negative side of the W phase. Then, at time T19 shortly after time T18, the gate signal control unit 50 transmits a gate signal "No" to the gate drive circuit 40b on the negative side of the U phase, the gate drive circuit 40d on the negative side of the V phase, and the gate drive circuit 40f on the negative side of the W phase. That is, the gate signal control unit 50 transmits the second gate signal from time T18 to time T19.

[0097] Here, in the power conversion device 20, the time interval from the transmission of the first gate signal (time T15) to the transmission of the second gate signal (time T18) is set to be longer than the transmission duration of the short-circuit signal "Yes". Thus, even if the short-circuit signal becomes "Yes" when the first gate signal is transmitted, the gate drive circuit 40 can properly receive the second gate signal.

[0098] exist Figure 4 In the example of , all the switch elements 30 corresponding to all the gate drive circuits 40 that malfunctioned due to static electricity return to a normal state before time T18. Figure 4 In the example of , there is no switching element 30 newly restored by sending the second gate signal.

[0099] Here, when static electricity is applied, it is unknown which gate drive circuit 40 malfunctions, and there are cases where multiple gate drive circuits 40 malfunction in parallel. Therefore, in the power conversion device 20, the first gate signal and the second gate signal are sent to return all the gate drive circuits 40 to a normal state. That is, in the power conversion device 20, the positive side gate drive circuit is brought into a normal state by the first gate signal, and the negative side gate drive circuit is brought into a normal state by the second gate signal.

[0100] In addition, when the gate drive circuit 40 detects a short circuit between the DC buses, it sends a forced signal to the switching element 30. Here, in the gate drive circuit 40, an abnormality may occur that a forced signal is not sent when a short circuit between the DC buses is detected. In this case, Figure 4 The output signal of the gate drive circuit 40b on the negative side of the U phase and the output signal of the gate drive circuit 40d on the negative side of the V phase are maintained in the "ON" state until time T19. However, in the power conversion device 20, at time T19, the output signal of the gate drive circuit 40b on the negative side of the U phase and the output signal of the gate drive circuit 40d on the negative side of the V phase can be changed to "No" according to the falling edge of the second gate signal. That is, even if an abnormality occurs in which the forced signal is not sent, the power conversion device 20 can more reliably restore the gate drive circuit 40 and the switching element 30.

[0101] In this case, although the reliability of recovery of the negative-side gate drive circuit is lowered compared to the method of transmitting the second gate signal, the recovery processing time can be shortened.

[0102] At time T20 later than time T19, the gate signal control unit 50 sends a gate signal "Yes" to the gate drive circuit 40a on the positive side of the U phase, the gate drive circuit 40c on the positive side of the V phase, and the gate drive circuit 40e on the positive side of the W phase. Then, at time T21 shortly after time T20, the gate signal control unit 50 sends a gate signal "No" to the gate drive circuit 40a on the positive side of the U phase, the gate drive circuit 40c on the positive side of the V phase, and the gate drive circuit 40e on the positive side of the W phase. That is, the gate signal control unit 50 sends the first gate signal again from time T20 to time T21.

[0103] Here, in the power conversion device 20, the time interval from the transmission of the second gate signal (time T18) to the transmission of the second first gate signal (time T20) is set to be longer than the transmission duration of the short-circuit signal "Yes". Thus, even if the short-circuit signal becomes "Yes" when the second gate signal is transmitted, the gate drive circuit 40 can properly receive the second first gate signal.

[0104] Next, at time T22 later than time T21, the gate signal control unit 50 sends a gate signal "yes" to the gate drive circuit 40b on the negative side of the U phase, the gate drive circuit 40d on the negative side of the V phase, and the gate drive circuit 40f on the negative side of the W phase. Then, at time T23 shortly after time T22, the gate signal control unit 50 sends a gate signal "no" to the gate drive circuit 40b on the negative side of the U phase, the gate drive circuit 40d on the negative side of the V phase, and the gate drive circuit 40f on the negative side of the W phase. That is, the gate signal control unit 50 sends the second gate signal again from time T22 to time T23.

[0105] The second sending of the first gate signal at time T20 to time T21 and the second sending of the second gate signal at time T22 to time T23 are performed to distinguish (distinguish) whether the short circuit between the DC buses is caused by static electricity or by a short circuit failure of the switching element 30.

[0106] If the short circuit between the DC buses is caused by static electricity, the switch element 30 can be restored to the "off" state if the first gate signal and the second gate signal are respectively sent once. However, if the short circuit between the DC buses is caused by a short circuit fault of the switch element 30, the switch element 30 cannot be restored to the "off" state even if the first gate signal and the second gate signal are respectively sent once.

[0107] Therefore, the gate signal control unit 50 repeats the first gate signal and the second gate signal alternately for multiple times (for example, twice). Then, when the gate signal control unit 50 detects a short circuit between the DC buses again when sending the first gate signal for the second time or later, it determines that at least one of the negative-side switching elements has a short circuit failure. In addition, when the gate signal control unit 50 detects a short circuit between the DC buses again when sending the second gate signal for the second time or later, it determines that at least one of the positive-side switching elements has a short circuit failure.

[0108] exist Figure 4 In the example of , the short-circuit signal is "No" at the time when the first gate signal is sent for the second time (time T20) and the time when the second gate signal is sent for the second time (time T22). Figure 4 In the example of , no short-circuit failure occurs in any of the switching elements 30. That is, in this case, it can be distinguished that the short circuit generated at the time T11 is caused by static electricity.

[0109] In addition, in the power conversion device 20, the time interval from the transmission of the second first gate signal (time T20) to the transmission of the second second gate signal (time T22) is set to be shorter than the transmission duration of the short-circuit signal "Yes". Therefore, in the power conversion device 20, the processing time can be shortened compared to a method in which the time interval between the second first gate signal and the second second gate signal is longer than the transmission duration of the short-circuit signal "Yes".

[0110] In this case, if the short-circuit signal becomes "yes" when the second first gate signal is sent, the gate drive circuit 40 does not receive the second second gate signal. However, for the short-circuit failure of the switch element 30, it is not necessary to determine the position of the switch element 30 where the short-circuit failure occurs, as long as it is known whether a short-circuit failure occurs in a certain switch element 30. That is, if the short-circuit signal becomes "yes" when the second first gate signal is sent, it is known at this moment that the short-circuit failure of the switch element 30 has occurred, so even if the second second gate signal cannot be received, there is actually no problem.

[0111] Figure 5 This is a timing chart for explaining the operation of the power conversion device 20 when a short-circuit failure occurs in the switching element 30 . Figure 5 The short-circuit signal shown shows a logical OR of the short-circuit signals sent from the respective gate drive circuits 40 .

[0112] For example, it is assumed that at time T30, the gate signal control unit 50 changes the gate signal sent to the gate drive circuit 40a on the positive side of the U phase from "yes" to "no". At this time, as shown by the circle mark B1 of the single-dot chain line, the switch element 30a on the positive side of the U phase is fixed in the "on" state and a short circuit fault occurs. That is, the switch element 30a on the positive side of the U phase will not become "off" and will remain "on" after time T30.

[0113] At time T31 later than time T30, when the switch element 30b on the negative side of the U phase is turned on, the DC buses are short-circuited by the switch elements 30a and 30b of the U phase. At this time, the gate drive circuits 40a and 40b of the U phase send a short-circuit signal “Yes” to the gate signal control unit 50 .

[0114] At time T32 later than time T31, the gate drive circuit 40a on the positive side of the U phase sends a forced signal to the switch element 30a, and the gate drive circuit 40b on the negative side of the U phase sends a forced signal to the switch element 30b. The switch element 30b turns "off" according to the forced signal. However, the switch element 30a does not turn "off" and remains "on" due to a short-circuit fault.

[0115] In addition, at time T33 later than time T32, the gate signal control unit 50, which receives the short-circuit signal "Yes", sets the gate signal sent to the gate drive circuit 40b on the negative side of the U phase to "No". In addition, at time T34 later than time T33, the gate drive circuits 40a and 40b of the U phase set the short-circuit signal to "No".

[0116] From time T35 later than time T34 to time T36, the gate signal control unit 50 transmits the first gate signal for the first time. At this time, no short circuit occurs between the DC buses in any of the U phase, the V phase, and the W phase.

[0117] From time T37 to time T38, which is a predetermined time after the transmission of the first gate signal, the gate signal control unit 50 transmits the second gate signal for the first time. At this time, since the switch element 30a on the positive side of the U phase is in the "on" state, the DC bus is short-circuited by the switch elements 30a and 30b of the U phase. The gate drive circuits 40a and 40b of the U phase transmit the short-circuit signal "yes" to the gate signal control unit 50.

[0118] At time T39 which is later than time T38 , a predetermined time has elapsed, and therefore the gate drive circuits 40 a and 40 b of the U phase set the short-circuit signal to “NO”.

[0119] The gate signal control unit 50 transmits the first gate signal for the second time from time T40 to time T41 after time T39 and a predetermined time after the transmission of the second gate signal. At this time, no short circuit occurs between the DC buses of any of the U phase, V phase, and W phase.

[0120] From time T42 to time T43, which is a predetermined time after the second transmission of the first gate signal, the gate signal control unit 50 transmits the second second gate signal. At this time, since the switch element 30a on the positive side of the U phase is in the "on" state, the DC bus is short-circuited by the switch elements 30a and 30b of the U phase. The gate drive circuits 40a and 40b of the U phase transmit the short-circuit signal "yes" to the gate signal control unit 50.

[0121] Since the gate signal control unit 50 receives the short-circuit signal "Yes" after the second gate signal is sent, it is determined that a short-circuit fault occurs in one of the positive-side switching elements. Thus, in the power conversion device 20, it is possible to distinguish whether the cause of the short circuit between the DC buses is caused by static electricity or by a short-circuit fault of the switching element 30.

[0122] Figure 6 This is a flowchart for explaining the operation of the gate signal control unit 50 of the power conversion device 20 . Figure 6 The power conversion device 20 is, for example, a power conversion device 20b connected to the second motor generator 14b.

[0123] The gate signal control unit 50 determines whether the short-circuit signal from the gate drive circuit 40 is "yes" (S100). When the short-circuit signal is not "yes" (the short-circuit signal is "no") (No in S100), the gate signal control unit 50 performs normal control (S110) and repeats the process of step S100. It should be noted that in normal control, the gate signal control unit 50 generates a gate signal according to the control of the vehicle control unit 24 and sends the generated gate signal to the gate drive circuit 40.

[0124] When the short-circuit signal is "yes" (yes in S100), the gate signal control unit 50 determines whether the motor generator 14 (for example, the second motor generator 14b) is rotating (S120). It should be noted that the rotation of the motor generator 14 can be detected by an encoder provided on the rotating shaft of the motor generator 14, or can be detected based on the current between the motor generator 14 and the power conversion device 20.

[0125] When the motor generator 14 is rotating (Yes in S120), the gate signal control unit 50 does not send the first gate signal and the second gate signal, but regards that a short circuit fault occurs in a certain switching element 30, and sends this information to the vehicle control unit 24 (S130), thereby terminating a series of processing. That is, if the motor generator 14 is rotating, the gate signal control unit 50 does not distinguish the cause of the short circuit between the DC buses.

[0126] Here, if the switch of the power conversion device 20 is stopped (normal control) while the motor generator 14 (second motor generator 14b) is rotating as a motor, the driving torque drops sharply and the behavior of the vehicle 1 becomes unstable. Therefore, in the power conversion device 20, the first gate signal and the second gate signal are not sent when the motor generator 14 is rotating.

[0127] Upon receiving the information that the short-circuit failure of the switching element 30 has occurred, the vehicle control unit 24 stops the second motor generator 14 b and switches the driving mode to fail-safe driving in which the vehicle is driven only by the engine 10 .

[0128] On the other hand, when the motor generator 14 is not rotating (is stopped) (No in S120), the gate signal control unit 50 determines whether a predetermined time has passed since the short-circuit signal "Yes" was received (S140). If the predetermined time has not passed (No in S140), the gate signal control unit 50 waits until the predetermined time has passed.

[0129] When the predetermined time has passed (Yes in S140), the gate signal control unit 50 sends the first gate signal to the gate drive circuit 40 (S150). Specifically, the gate signal control unit 50 sends the gate signal "Yes" in parallel to the positive side gate drive circuit, and then immediately sends the gate signal "No" in parallel to the positive side gate drive circuit. It should be noted that the time interval between "Yes" and "No" of the gate signal at this time is set to, for example, the shortest time that the gate drive circuit 40 can properly recognize the gate signal as a pulse.

[0130] Next, the gate signal control unit 50 determines whether a predetermined time has passed since the first gate signal was transmitted (S160). If the predetermined time has not passed (No in S160), the gate signal control unit 50 waits until the predetermined time has passed.

[0131] When the predetermined time has passed (Yes in S160), the gate signal control unit 50 sends the second gate signal to the gate drive circuit 40 (S170). Specifically, the gate signal control unit 50 sends the gate signal "Yes" in parallel to the negative-side gate drive circuit, and then immediately sends the gate signal "No" in parallel to the negative-side gate drive circuit. It should be noted that the time interval between "Yes" and "No" of the gate signal at this time is set to, for example, the shortest time that the gate drive circuit 40 can properly recognize the gate signal as a pulse.

[0132] Next, the gate signal control unit 50 determines whether a predetermined time has passed since the second gate signal was transmitted (S180). If the predetermined time has not passed (No in S180), the gate signal control unit 50 waits until the predetermined time has passed.

[0133] When the predetermined time has passed (Yes in S180), the gate signal control unit 50 transmits the first gate signal for the second time (S190). Specifically, the gate signal control unit 50 transmits the gate signal "Yes" to the positive side gate drive circuit in parallel, and then immediately transmits the gate signal "No" to the positive side gate drive circuit in parallel.

[0134] Next, the gate signal control unit 50 determines whether the short-circuit signal "Yes" is received again within a predetermined time from the second transmission of the first gate signal (S200). In the case of receiving the short-circuit signal "Yes" (Yes in S200), the gate signal control unit 50 regards that a short-circuit fault occurs in one of the negative-side switching elements, and sends this information to the vehicle control unit 24 (S130), thereby ending a series of processing. Then, the vehicle control unit 24 stops the second motor generator 14b and switches to fail-safe driving.

[0135] On the other hand, when the short-circuit signal "Yes" is not received (No in S200), the gate signal control unit 50 sends the second gate signal for the second time (S210). Specifically, the gate signal control unit 50 sends the gate signal "Yes" to the negative-side gate drive circuit in parallel, and then immediately sends the gate signal "No" to the negative-side gate drive circuit in parallel.

[0136] Next, the gate signal control unit 50 determines whether the short-circuit signal "Yes" is received again within a predetermined time from the second transmission of the second gate signal (S220). In the case of receiving the short-circuit signal "Yes" (Yes in S220), the gate signal control unit 50 regards that a short-circuit fault occurs in one of the positive-side switching elements, and sends the information to the vehicle control unit 24 (S130), thereby ending a series of processing. Then, the vehicle control unit 24 stops the second motor generator 14b and shifts to fail-safe driving.

[0137] On the other hand, if the short-circuit signal "Yes" is not received (No in S220), the gate signal control unit 50 regards the short-circuit as caused by static electricity, and the gate drive circuit 40 and the switch element 30 return to a normal state, thereby ending a series of processing. In this case, the vehicle control unit 24 does not shift to fail-safe driving, but maintains the current driving mode.

[0138] Thus, the gate signal control unit 50 transmits the first gate signal and the second gate signal only when the motor generator 14 (the second motor generator 14 b ) is stopped.

[0139] Here, since the second motor generator 14b is the driving source of the vehicle 1, when the second motor generator 14b is rotating, the vehicle 1 is traveling. Although a passenger (person) may touch the power conversion device 20 when the vehicle 1 is traveling, this possibility is low.

[0140] On the other hand, the first motor generator 14a sometimes rotates for power generation even when the vehicle 1 is stopped. In addition, when the vehicle 1 is stopped, a person is more likely to approach the trunk of the vehicle 1 and touch the power conversion device 20 than when the vehicle 1 is traveling. That is, when the first motor generator 14a is rotating, static electricity is more likely to be applied to the power conversion device 20 than when the second motor generator 14b is rotating.

[0141] Therefore, the power conversion device 20a connected to the first motor generator 14a is also connected to the first motor generator 14a. Figure 6 Similarly, when a short circuit occurs between the DC buses due to a malfunction caused by static electricity, the switching element 30 can be restored to the “off” state by sending the first gate signal and the second gate signal.

[0142] Here, if the switch of the power conversion device 20 is stopped (normal control) while the first motor generator 14a is rotating as a generator, the voltage induced by the first motor generator 14a cannot be controlled, and an overcurrent regenerative current is input to the battery 22, which may damage the battery 22.

[0143] In addition, the first motor generator 14a is basically not used for driving the vehicle 1. Therefore, there is no problem even if the first motor generator 14a rotating as a generator is stopped.

[0144] Therefore, in the vehicle 1, when there is a high possibility that the power conversion device 20a connected to the first motor generator 14a is touched by a person (for example, when the trunk door and / or rear door are open), the first motor generator 14a is stopped in advance.

[0145] Figure 7 This is a flowchart for explaining the operation of the vehicle control unit 24 when the vehicle 1 is parked. Figure 1 Although omitted in the figure, a rear door sensor for detecting the opening and closing of the rear door and a trunk door sensor for detecting the opening and closing of the trunk door are provided in the vehicle 1. When the rear door is opened, the rear door sensor sends a rear door signal "yes" to the vehicle control unit 24. In addition, when the trunk door is opened, the trunk door sensor sends a trunk door signal "yes" to the vehicle control unit 24.

[0146] exist Figure 7 In the process, the vehicle control unit 24 determines whether or not one or both of the rear door signal and the trunk door signal are "yes" (S300).

[0147] When both the rear door signal and the trunk door signal are not “Yes” (No in S300 ), the vehicle control unit 24 ends a series of processes.

[0148] When one or both of the rear door signal and the trunk door signal are "yes" (yes in S300), the vehicle control unit 24 determines whether the first motor generator 14a is rotating (S310). When the first motor generator 14a is not rotating (is stopped) (no in S310), the vehicle control unit 24 ends a series of processes and maintains the first motor generator 14a stopped.

[0149] On the other hand, when the first motor generator 14a is rotating (Yes in S310), the vehicle control unit 24 stops the first motor generator 14a (S320), and ends a series of processes.

[0150] Thus, in the vehicle 1, when the trunk door or the rear door is opened, the first motor generator 14a is stopped in advance. Therefore, in the vehicle 1, even if static electricity is applied to the power conversion device 20a connected to the first motor generator 14a, the first gate signal and the second gate signal can be transmitted in the state where the first motor generator 14a is stopped. As a result, in the vehicle 1, damage to the battery 22 can be prevented.

[0151] As described above, when the gate signal control unit 50 of the power conversion device 20 of the present embodiment detects a short circuit between the DC buses, it sends a first gate signal to the positive side gate drive circuit that temporarily turns on the positive side switch element and then turns it off, and sends a second gate signal to the negative side gate drive circuit that temporarily turns on the negative side switch element and then turns it off.

[0152] Therefore, according to the power conversion device 20 of this embodiment, when the gate drive circuit 40 malfunctions due to static electricity, the output signal of the gate drive circuit 40 can be restored to a normal state. As a result, in the power conversion device 20 of this embodiment, the switching element 30 can be restored to the "off" state, and it is avoided that it is erroneously judged as caused by a short-circuit fault of the switching element 30.

[0153] The gate signal control unit 50 transmits the first gate signal and the second gate signal at different transmission times. Therefore, in the power converter 20 of this embodiment, short circuits between DC buses caused by coincidence of transmission times of the first gate signal and the second gate signal can be avoided.

[0154] In addition, the gate signal control unit 50 transmits the second gate signal after a predetermined time has passed since the transmission of the first gate signal. Therefore, in the power conversion device 20 of the present embodiment, the gate drive circuit 40 can appropriately receive the second gate signal.

[0155] In addition, the gate signal control unit 50 repeats the transmission of the first gate signal and the transmission of the second gate signal alternately for multiple times. Furthermore, when the gate signal control unit 50 detects a short circuit between the DC buses again when transmitting the first gate signal for the second time or later, it determines that a short circuit fault has occurred in the negative side switch element, or when the gate signal control unit 50 detects a short circuit between the DC buses again when transmitting the second gate signal for the second time or later, it determines that a short circuit fault has occurred in the positive side switch element. Therefore, in the power conversion device 20 of the present embodiment, it is possible to distinguish whether the cause of the short circuit between the DC buses is caused by static electricity or by a short circuit fault of the switch element 30.

[0156] In addition, when the gate signal control unit 50 detects a short circuit between the DC buses, the first gate signal and the second gate signal are not sent when the electric generator 14 is already rotating, and it is regarded as a short circuit fault in the positive side switching element or the negative side switching element. In addition, when the gate signal control unit 50 detects a short circuit between the DC buses, the electric generator 14 is already stopped, and the first gate signal and the second gate signal are sent, so that if the short circuit is caused by a malfunction of one or both of the positive side gate drive circuit and the negative side gate drive circuit, it is recovered from the short circuit. Therefore, with respect to the power conversion device 20 of the present embodiment, in the vehicle 1 to which the power conversion device 20 is applied, it is possible to prevent the behavior of the vehicle 1 from becoming unstable and / or the battery 22 from being damaged.

[0157] In the vehicle 1 of the present embodiment, an insulating material such as a non-metallic thin plate may be provided on a metal portion of the housing accommodating the power conversion device 20. According to this aspect, application of static electricity to the power conversion device 20 can be suppressed.

[0158] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, it is obvious that the present invention is not limited to such embodiments. It is obvious to those skilled in the art that various variations or modifications can be thought of within the scope of the claims, and it is necessary to understand that these variations or modifications also belong to the technical scope of the present invention.

[0159] For example, the gate signal control unit 50 of the above embodiment sends the first gate signal and the second gate signal alternately twice. However, the number of times the first gate signal and the second gate signal are sent is not limited to twice each. For example, the gate signal control unit 50 may also send the first gate signal and the second gate signal alternately three or more times.

[0160] In addition, the gate signal control unit 50 may send the first gate signal and the second gate signal once respectively. In this case, although the cause of the short circuit between the DC buses cannot be distinguished, at least the switch element 30 can be restored to the "off" state when a short circuit occurs between the DC buses due to a malfunction caused by static electricity.

[0161] In addition, the gate signal control unit 50 of the above embodiment sends the second gate signal after sending the first gate signal. However, the gate signal control unit 50 may also send the first gate signal after sending the second gate signal. In this way, even when a short circuit occurs between the DC buses due to a malfunction caused by static electricity, the switch element 30 can be restored to the "off" state.

[0162] In addition, the gate signal control unit 50 of the above embodiment transmits the first gate signal and the second gate signal at different transmission times. However, the gate signal control unit 50 may transmit the first gate signal and the second gate signal in parallel.

[0163] In addition, the vehicle 1 of the above embodiment is a series-connected hybrid vehicle. However, the vehicle 1 is not limited to a series-connected hybrid vehicle, and may be, for example, a parallel hybrid vehicle or a series hybrid vehicle. In addition, the vehicle 1 is not limited to a hybrid vehicle, and may be an electric vehicle.

[0164] Industrial Applicability

[0165] The present invention can be used in a power conversion device that turns on and off a switching element by a gate drive circuit, and a vehicle having the power conversion device.

Claims

1. A power conversion device, characterized in that: have: A positive-side switching element, which is arranged between the positive-side DC bus and the output node; A negative-side switching element, which is arranged between the negative-side DC bus and the output node; A positive-side gate driving circuit, which turns on and off the positive-side switching element; a negative electrode side gate driving circuit, which turns on and off the negative electrode side switching element; and a gate signal control unit that sends a gate signal indicating the on / off state of the positive-side switching element to the positive-side gate drive circuit, and sends a gate signal indicating the on / off state of the negative-side switching element to the negative-side gate drive circuit, When the gate signal control unit detects a short circuit between the positive-side DC bus and the negative-side DC bus, the gate signal control unit sends a first gate signal to the positive-side gate drive circuit to temporarily turn on the positive-side switch element and then turn it off, and sends a second gate signal to the negative-side gate drive circuit to temporarily turn on the negative-side switch element and then turn it off. The gate signal control unit transmits the first gate signal and the second gate signal in a manner that the transmission timings are different. When the gate signal control unit detects a short circuit between the positive-side DC bus and the negative-side DC bus, if the motor generator connected to the output node is already rotating, the first gate signal and the second gate signal are not sent, and it is regarded that a short circuit fault occurs in the positive-side switching element or the negative-side switching element. When the gate signal control unit detects a short circuit between the positive-side DC bus and the negative-side DC bus, the electric generator is already stopped. By sending the first gate signal and the second gate signal, the electric generator is recovered from the short circuit if the short circuit is caused by a malfunction of one or both of the positive-side gate drive circuit and the negative-side gate drive circuit.

2. The power conversion device according to claim 1, characterized in that: The gate signal control unit transmits one of the first gate signal and the second gate signal after a predetermined time has passed since the other one of the first gate signal and the second gate signal was transmitted.

3. The power conversion device according to claim 2, characterized in that: The gate signal control unit repeats sending of the first gate signal and sending of the second gate signal alternately a plurality of times.

4. The power conversion device according to claim 3, characterized in that: When the gate signal control unit detects a short circuit between the positive side DC bus and the negative side DC bus again when sending the first gate signal for the second time or later, it determines that a short circuit fault has occurred in the negative side switching element, or when the gate signal control unit detects a short circuit between the positive side DC bus and the negative side DC bus again when sending the second gate signal for the second time or later, it determines that a short circuit fault has occurred in the positive side switching element.

5. A vehicle, characterized in that: have: a motor generator that generates electricity based on the drive of the engine; a power conversion device that transmits and receives electric power to and from the motor generator; and a vehicle control unit that controls the power conversion device, The power conversion device comprises: A positive-side switching element, which is arranged between the positive-side DC bus and the output node; A negative-side switching element, which is arranged between the negative-side DC bus and the output node; A positive-side gate driving circuit, which turns on and off the positive-side switching element; a negative electrode side gate driving circuit, which turns on and off the negative electrode side switching element; and a gate signal control unit that sends a gate signal indicating the on / off state of the positive-side switching element to the positive-side gate drive circuit, and sends a gate signal indicating the on / off state of the negative-side switching element to the negative-side gate drive circuit, When the gate signal control unit detects a short circuit between the positive-side DC bus and the negative-side DC bus, the gate signal control unit sends a first gate signal to the positive-side gate drive circuit to temporarily turn on the positive-side switch element and then turn it off, and sends a second gate signal to the negative-side gate drive circuit to temporarily turn on the negative-side switch element and then turn it off. The gate signal control unit transmits the first gate signal and the second gate signal in a manner that the transmission timings are different. The vehicle control unit causes the power conversion device to stop the motor generator when one or both of the trunk door and the rear door are opened, When the gate signal control unit detects a short circuit between the positive-side DC bus and the negative-side DC bus, if the motor generator connected to the output node is already rotating, the first gate signal and the second gate signal are not sent, and it is regarded that a short circuit fault occurs in the positive-side switching element or the negative-side switching element. When the gate signal control unit detects a short circuit between the positive-side DC bus and the negative-side DC bus, the electric generator is already stopped. By sending the first gate signal and the second gate signal, the electric generator is recovered from the short circuit if the short circuit is caused by a malfunction of one or both of the positive-side gate drive circuit and the negative-side gate drive circuit.

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