JP2009207317A - Vehicle driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To diagnose whether or not an inverter protection function normally operates even when a high voltage is not applied to an inverter. <P>SOLUTION: A control unit 5 in a vehicle driving device controls an operating state of a switching circuit 23 and detects an inverter voltage V1 when an inverter protection device 4 does not operate and an inverter voltage V2 when the inverter protection device 4 operates so as to compare them with each other. Consequently, it is possible to diagnose whether or not the inverter protection device 4 normally operates. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle drive device that drives a vehicle by converting power generated by a generator into AC power by an inverter and supplying the AC power to a motor of the vehicle.

2. Description of the Related Art Conventionally, a vehicle drive device that drives a vehicle by converting generated power of a generator driven by an internal combustion engine of the vehicle into AC power by an inverter and supplying the AC power to the motor of the vehicle is known. In such a vehicle drive device, when the electric motor is rotated in the direction opposite to the control direction by an external force, a regenerative state is established, and there is a difference in response speed between the generator and the electric motor. In such a case, a high voltage may be applied to the inverter when surplus power is generated due to an imbalance between the power supply and demand between the generator and the motor. From this background, when the inverter voltage exceeds the set voltage, control is performed so that a high voltage is not applied to the inverter by flowing current to the resistance side via the bypass means and consuming excess power as heat. A vehicle drive device having an inverter protection function has been proposed (see Patent Document 1).
JP 2001-352664 A

  In the above prior art, it is necessary to diagnose whether or not the inverter protection function operates normally in case a high voltage state actually occurs. However, in order to diagnose whether the inverter protection function operates normally, it is necessary to actually apply a high voltage to the inverter. If the inverter protection function does not operate normally at this time, the inverter There is a risk of destruction. From such a background, it is desired to provide an inverter protection function capable of diagnosing whether or not the inverter operates normally even when a high voltage is not applied to the inverter.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to drive a vehicle having an inverter protection function capable of diagnosing whether or not the inverter operates normally even when a high voltage is not applied to the inverter. To provide an apparatus.

  The vehicle drive apparatus according to the first aspect of the present invention diagnoses the operating state of the inverter protection means based on the inverter voltage detection means for detecting the voltage applied to the inverter and the voltage value detected by the inverter voltage detection means. Diagnostic means. A vehicle drive apparatus according to a second aspect of the present invention includes a current detection unit that detects a current flowing through a bypass resistor circuit, and a diagnosis that diagnoses the operating state of the inverter protection unit based on the current value detected by the current detection unit. Means.

  According to the vehicle drive device of the present invention, it is possible to diagnose whether the inverter protection function operates normally even when a high voltage is not applied to the inverter.

  Hereinafter, a configuration of a vehicle drive device according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
First, the configuration of the vehicle drive device according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3.

[Configuration of vehicle drive device]
As shown in FIG. 1, the vehicle drive apparatus according to the first embodiment of the present invention converts electric power generated by a generator 1 driven by an internal combustion engine of a vehicle (not shown) into an electric motor drive inverter circuit (hereinafter abbreviated as an inverter). 2) Drives the vehicle by converting it into AC power at 2 and supplying it to the motor 3, and includes a generator 1, an inverter 2, an electric motor 3, an inverter protection device 4, corresponding to the inverter protection means according to the present invention, and The control unit 5 corresponding to the diagnostic means according to the present invention is provided as a main component. The generator 1 is driven by the rotational power of the internal combustion engine of the vehicle, and outputs generated power (generator outputs (+), (−)) to the inverter 2. The magnitude of the generated power of the generator 1 is controlled by the magnetic flux of the permanent magnet 11 and the magnetic flux of the field coil L connected to the power source 12 and controlled by the generator field control signal output from the control unit 5.

  The inverter 2 drives the motor 3 using the generated power input from the generator 1 in accordance with an inverter control signal from the control unit 5. The electric motor 3 is driven by AC power supplied from the inverter 2 and drives the vehicle by transmitting torque to the road surface via a differential device (not shown) and a tire. The inverter protection device 4 is connected between the generator 1 and the inverter 2, and is connected to the inverter 2 in parallel. The inverter voltage detection circuit 21, the high voltage detection circuit 22, and the inverter corresponding to the inverter voltage detection means according to the present invention. 2 is provided with a bypass resistor circuit R1 connected in parallel to 2 and a switching circuit 23 corresponding to the operating means according to the present invention connected in series to the bypass resistor circuit R1.

  The inverter voltage detection circuit 21 detects a voltage applied to the inverter 2 (hereinafter abbreviated as an inverter voltage), and outputs a detection value to the high voltage detection circuit 22 and the control unit 5. The high voltage detection circuit 22 determines whether or not the inverter voltage detected by the inverter voltage detection circuit 21 is equal to or higher than a set value, and switches the operation state to a closed state when the inverter voltage is equal to or higher than the set value. An operation signal is output to the switching circuit 23. The switching circuit 23 is switched between open and closed states in accordance with switching circuit operation signals from the high voltage detection circuit 22 and the control unit 5. When the switching circuit 23 is in the closed state, a high voltage is applied to the inverter 2 by flowing a current through the bypass resistor circuit R1. Is suppressed from being applied. The switching circuit 23 outputs a signal indicating whether the current operation state is an open state or a closed state to the control unit 5 as a switching circuit operation state signal. When the switching circuit 23 is in the closed state, the bypass resistor circuit R1 converts energy supplied from the generator 1 into heat, thereby releasing energy and lowering the inverter voltage. The control unit 5 controls operations of the inverter 2, the switching circuit 23, and the field coil L.

[Inverter protection function diagnosis processing]
The vehicle drive device having such a configuration diagnoses whether or not the inverter protection device 4 operates normally by executing the following inverter protection function diagnosis processing (hereinafter abbreviated as diagnosis processing). Hereinafter, with reference to the flowchart shown in FIG. 2, the flow of the operation of the vehicle drive device when executing this diagnosis processing will be described.

  The flowchart shown in FIG. 2 starts at the timing when the predetermined operation state is reached, and the diagnosis process proceeds to the process of step S1. In the present embodiment, a state in which the internal combustion engine drives the generator 1 at a rotational speed equivalent to idling and the field control of the field coil L by the control unit 5 is stopped is defined as a predetermined operation state.

  In the process of step S1, the control unit 5 determines whether or not the inverter voltage detected by the inverter voltage detection circuit 21 is equal to or higher than a predetermined determination threshold value Vth1. As a result of the determination, when the inverter voltage is less than the predetermined determination threshold value Vth1, the control unit 5 ends the series of diagnostic processes. On the other hand, when the inverter voltage is equal to or higher than the predetermined determination threshold value Vth1, the control unit 5 advances the diagnosis process to the process of step S2. In general, the inverter voltage is always constant when the internal combustion engine drives the generator 1 at a rotational speed equivalent to idling and the field control of the field coil L by the control unit 5 is stopped (shown in FIG. 3). Between time T = 0 and T1). Accordingly, the determination threshold value Vth1 is set to a predetermined voltage value equal to or lower than this constant voltage.

  In the process of step S2, the control unit 5 outputs a switching circuit operation signal for switching the operation state of the switching circuit 23 to the open state, and the inverter voltage when the switching circuit 23 is in the open state via the inverter voltage detection circuit 21. V1 is detected (time T = T1 shown in FIG. 3). Thereby, the process of step S2 is completed and the diagnostic process proceeds to the process of step S3.

  In the process of step S3, the control unit 5 outputs a switching circuit operation signal for switching the operation state of the switching circuit 23 to the closed state, thereby causing the current from the generator 1 to flow through the bypass resistor circuit R1 (shown in FIG. 3). Time T = T2). Thereby, the process of step S3 is completed and a diagnostic process progresses to the process of step S4.

  In the process of step S4, the control unit 5 detects the inverter voltage V2 when the switching circuit 23 is in the closed state via the inverter voltage detection circuit 21 (time T = T3 shown in FIG. 3). Thereby, the process of step S4 is completed, and the diagnostic process proceeds to the process of step S5.

  In the process of step S5, the control unit 5 calculates the difference value between the inverter voltage V1 detected by the process of step S2 and the inverter voltage V2 detected by the process of step S4 as the voltage difference DV. Thereby, the process of step S5 is completed and the diagnostic process proceeds to the process of step S6.

  In the process of step S6, the control unit 5 determines whether or not the voltage difference DV calculated by the process of step S5 is greater than or equal to a predetermined determination threshold value Vth2 (see FIG. 3). As a result of the determination, when the voltage difference DV is equal to or greater than the predetermined determination threshold Vth2, the control unit 5 has the voltage drop that is equal to or higher than the predetermined determination threshold Vth2, so that the inverter protection device 4 is operating normally. Judgment is made and the diagnosis process proceeds to the process of step S8. On the other hand, when the voltage difference DV is less than the predetermined determination threshold value Vth2, the control unit 5 advances the diagnosis process to the process of step S7. As already described, the inverter voltage is always constant when the internal combustion engine drives the generator 1 at a rotational speed equivalent to idling and the field control of the field coil L by the control unit 5 is stopped. . Therefore, the determination threshold value Vth2 is set to a predetermined voltage value equal to or lower than a voltage value determined by the constant voltage and the resistance value of the bypass resistor circuit R1.

  In the process of step S7, the control unit 5 determines that the voltage drop of the inverter voltage by the inverter protection device 4 is not normally performed, and stops the control of the inverter 2 and the field coil L, whereby the generator 1 Is stopped, and the operation of the electric motor 3 is stopped. Thereby, the process of step S7 is completed, and the diagnostic process proceeds to the process of step S8.

  In the process of step S8, the control unit 5 outputs a switching circuit operation signal for switching the operation state of the switching circuit 23 to the open state (time T = T4 shown in FIG. 3). Thereby, the process of step S8 is completed and a series of diagnostic processes are completed.

  As is apparent from the above description, in the vehicle drive device according to the first embodiment of the present invention, the inverter protection device 4 is not operated by the control unit 5 controlling the operating state of the switching circuit 23. Since the inverter voltage V1 and the inverter voltage V2 when the inverter protection device 4 is operating are detected and compared to diagnose whether or not the inverter protection device 4 operates normally, a high voltage is applied to the inverter 2 It is possible to diagnose whether or not the inverter protection device 4 operates normally in a state where no voltage is applied.

[Second Embodiment]
Next, with reference to FIG. 4 thru | or FIG. 6, the structure of the vehicle drive device which becomes the 2nd Embodiment of this invention is demonstrated.

[Configuration of vehicle drive device]
As shown in FIG. 4, the vehicle drive apparatus according to the second embodiment of the present invention includes a current detection circuit 24 corresponding to the current detection means according to the present invention in addition to the configuration of the vehicle drive apparatus shown in FIG. . The current detection circuit 24 is provided between the bypass resistor circuit R1 and the switching circuit 23, detects a current flowing through the bypass resistor circuit R1, and outputs the detected value to the control unit 5 as a bypass circuit current value. Since the other configuration is the same as the configuration of the vehicle drive device according to the first embodiment, the description thereof will be omitted below.

[Inverter protection function diagnosis processing]
The vehicle drive device having such a configuration diagnoses whether or not the inverter protection device 4 operates normally by executing the following inverter protection function diagnosis processing (hereinafter abbreviated as diagnosis processing). Hereinafter, with reference to the flowchart shown in FIG. 5, the flow of the operation of the vehicle drive device when executing this diagnosis processing will be described.

  The flowchart shown in FIG. 5 starts at the timing when the predetermined operation state is reached, and the diagnosis process proceeds to step S11. In the present embodiment, a state in which the internal combustion engine drives the generator 1 at a rotational speed equivalent to idling and the field control of the field coil L by the control unit 5 is stopped is defined as a predetermined operation state. Further, since the process of step S11 is the same as the process of step S1, the description will be omitted below, and the process will be described from the process of step S12.

  In the process of step S12, the control unit 5 outputs a switching circuit operating signal for switching the operating state of the switching circuit 23 to the open state, and when the switching circuit 23 is in the open state via the current detection circuit 24, the bypass resistor circuit The current I1 flowing through R1 is detected (time T = T1 shown in FIG. 5). Thereby, the process of step S12 is completed and the diagnostic process proceeds to the process of step S13.

  In the process of step S13, the control unit 5 determines whether or not the current I1 detected by the process of step S12 is equal to or less than a predetermined determination threshold value Ith1. As a result of the determination, if the current I1 is less than or equal to the predetermined determination threshold value Ith1, the control unit 5 determines that the inverter protection device 4 is operating normally, and advances the diagnosis process to the process of step S15. On the other hand, if the current I1 is not less than or equal to the predetermined determination threshold value Ith1, the control unit 5 advances the diagnosis process to the process of step S14. The determination threshold value Ith1 can be exemplified by a current value in a state where no current flows through the bypass resistor circuit R1. When the current I1 is larger than the determination threshold value Ith1, it can be determined that the inverter protection circuit 4 is abnormal due to a short circuit failure of the switching circuit 23 or the like.

  In the process of step S14, the inverter protection device 4 operates abnormally because the control unit 5 is energized even though the switching circuit 23 is in an open state or power is not consumed by the bypass resistor circuit R1. The control of the generator 1 is stopped by stopping the control of the inverter 2 and the field coil L, and the operation of the electric motor 3 is stopped. Thereby, the process of step S14 is completed, and the diagnosis process proceeds to the process of step S18.

  In the process of step S15, the control unit 5 outputs a switching circuit operation signal for switching the operation state of the switching circuit 23 to the closed state, thereby causing the current from the generator 1 to flow through the bypass resistor circuit R1 (shown in FIG. 5). Time T = T2). Thereby, the process of step S15 is completed, and the diagnostic process proceeds to the process of step S16.

  In the process of step S16, the control unit 5 detects the current I2 flowing through the bypass resistor circuit R1 when the switching circuit 23 is in the closed state via the current detection circuit 24 (time T = T3 shown in FIG. 5). Thereby, the process of step S16 is completed, and the diagnostic process proceeds to the process of step S17.

  In the process of step S17, the control unit 5 determines whether or not the current I2 detected by the process of step S16 is greater than or equal to a predetermined determination threshold value Ith2. As a result of the determination, if the current I2 is equal to or greater than the predetermined determination threshold value Ith2, the control unit 5 determines that the inverter protection device 4 is operating normally, and advances the diagnostic process to step S18. On the other hand, when the current I2 is less than the predetermined determination threshold value Ith2, the control unit 5 advances the diagnosis process to the process of step S14. Generally, the generated power of the generator 3 is always constant when the internal combustion engine drives the generator 1 at the number of revolutions when idling and the field control of the field coil L by the control unit 5 is stopped. Therefore, the determination threshold value Ith2 is set to a predetermined voltage value equal to or less than the current value determined by the constant power and the resistance value of the bypass resistor circuit R1.

  In the process of step S18, the control unit 5 outputs a switching circuit operation signal for switching the operation state of the switching circuit 23 to an open state (time T = T4 shown in FIG. 5). Thereby, the process of step S18 is completed and a series of diagnostic processes are completed.

  As is apparent from the above description, in the vehicle drive device according to the second embodiment of the present invention, the inverter protection device 4 is not operated by the control unit 5 controlling the operating state of the switching circuit 23. Sometimes the current I1 flowing through the bypass resistor circuit R1 and the current I2 flowing through the bypass resistor circuit R1 when the inverter protection device 4 is operating are detected, and the detected currents I1 and I2 are compared with predetermined threshold values Ith1 and Ith2. By doing so, it is diagnosed whether or not the inverter protection device 4 operates normally. Therefore, it is possible to diagnose whether or not the inverter protection device 4 operates normally without applying a high voltage to the inverter 2. .

[Third Embodiment]
Next, with reference to FIG. 7 and FIG. 8, the structure of the vehicle drive device which becomes the 3rd Embodiment of this invention is demonstrated.

[Configuration of vehicle drive device]
Since the structure of the vehicle drive device which becomes the 3rd Embodiment of this invention is the same as the structure of the vehicle drive device which becomes 1st Embodiment, the description is abbreviate | omitted below.

[Inverter protection function diagnosis processing]
In the vehicle drive device having such a configuration, a high voltage is applied to the inverter 2 by executing an inverter protection function diagnosis process (hereinafter abbreviated as a diagnosis process) shown below, and the high voltage detection circuit 22 is switched to a switching circuit. Even if the inverter protection device 4 is operated by setting the operation state of 23 to the closed state, it is possible to diagnose whether the inverter protection device 4 operates normally. Hereinafter, with reference to the flowchart shown in FIG. 7, the flow of operation of the vehicle drive device when executing this diagnosis processing will be described.

  The flowchart shown in FIG. 7 starts at the timing when the predetermined operation state is reached, and the diagnosis process proceeds to the process of step S21. Since the process of step S21 is the same as the process of step S1, the description will be omitted below and the process of step S22 will be described.

  In the process of step S22, the control unit 5 determines whether or not the inverter voltage detected by the inverter voltage detection circuit 21 is equal to or higher than the high voltage determination threshold Vth3. As a result of the determination, when the inverter voltage is less than the high voltage determination threshold Vth3, the control unit 5 ends the series of diagnostic processes. On the other hand, when the inverter voltage is equal to or higher than the high voltage determination threshold Vth3, the control unit 5 advances the diagnosis process to the process of step S23. As the high voltage determination threshold Vth3, for example, a voltage value that is not less than the maximum value of the control voltage of the electric motor 3 and less than the maximum value of the withstand voltage value of the inverter 2 can be exemplified.

  In the process of step S23, the control unit 5 determines whether or not the operating state of the switching circuit 23 is an open state. As a result of the determination, when the operating state of the switching circuit 23 is an open state, the control unit 5 advances the diagnosis process to the process of step S24. On the other hand, when the operation state of the switching circuit 23 is the closed state, the control unit 5 advances the diagnosis process to the process of step S25.

  In the process of step S24, the control unit 5 measures the inverter voltage V21 when the switching circuit 23 is in the open state by the inverter voltage detection circuit 21 (time T = T1 shown in FIG. 8), and the high voltage detection circuit 22 When the inverter voltage becomes equal to or higher than the high voltage determination threshold Vth3, a signal for closing the operation state of the switching circuit 23 is output (time T = T2 shown in FIG. 8). Thereby, the process of step S24 is completed and the diagnostic process proceeds to the process of step S26.

  In the process of step S25, the control unit 5 measures the inverter voltage V22 when the switching circuit 23 is in the closed state by the inverter voltage detection circuit 21 (time T = T3 shown in FIG. 8). Thereby, the process of step S25 is completed, and the diagnostic process proceeds to the process of step S26.

  In the process of step S26, the control unit 5 calculates the difference value between the inverter voltage V21 measured by the process of step S24 and the inverter voltage V22 measured by the process of step S25 as the voltage difference DV2. Thereby, the process of step S26 is completed and the diagnostic process proceeds to the process of step S27.

  In the process of step S27, the control unit 5 determines whether or not the voltage difference DV2 calculated by the process of step S26 is greater than or equal to a predetermined determination threshold value Vth2. As a result of the determination, if the voltage difference DV2 is greater than or equal to the predetermined determination threshold Vth2, there is a voltage drop in the inverter voltage that is greater than or equal to the predetermined determination threshold Vth2. And the series of diagnostic processes is terminated. On the other hand, when the voltage difference DV2 is less than the predetermined determination threshold value Vth2, the control unit 5 advances the diagnosis process to the process of step S28.

  In the process of step S28, the control unit 5 determines that the voltage drop of the inverter voltage by the inverter protection device 4 is not normally performed, and stops the control of the inverter 2 and the field coil L, whereby the generator 1 Is stopped, and the operation of the electric motor 3 is stopped. Thereby, the process of step S28 is completed and a series of diagnostic processes are completed.

  As is apparent from the above description, in the vehicle drive device according to the third embodiment of the present invention, the control unit 5 compares the difference in inverter voltage before and after the inverter protection device 4 is operated with a predetermined determination threshold value. Therefore, whether the inverter protection device 4 operates normally even when a high voltage is applied to the inverter 2 and the inverter protection device 4 operates. Can be diagnosed. In addition, the vehicle drive device of this embodiment can be used together with the vehicle drive device of 1st Embodiment, or can each be used independently.

[Fourth Embodiment]
Next, with reference to FIG. 9 and FIG. 10, the structure of the vehicle drive device which becomes the 4th Embodiment of this invention is demonstrated.

[Configuration of vehicle drive device]
Since the structure of the vehicle drive device which becomes the 4th Embodiment of this invention is the same as the structure of the vehicle drive device which becomes 2nd Embodiment, the description is abbreviate | omitted below.

[Inverter protection function diagnosis processing]
In the vehicle drive device having such a configuration, a high voltage is applied to the inverter 2 by executing an inverter protection function diagnosis process (hereinafter abbreviated as a diagnosis process) shown below, and the high voltage detection circuit 22 is switched to a switching circuit. Even if the inverter protection device 4 is operated by setting the operation state of 23 to the closed state, it is possible to diagnose whether the inverter protection device 4 operates normally. Hereinafter, with reference to the flowchart shown in FIG. 9, the flow of the operation of the vehicle drive device when executing this diagnosis processing will be described.

  The flowchart shown in FIG. 9 starts at the timing when the predetermined operation state is reached, and the diagnosis process proceeds to step S31. Since the process in step S31 is the same as the process in step S1, the description will be omitted below and the process from step S32 will be described.

  In the process of step S32, the control unit 5 determines whether or not the inverter voltage detected by the inverter voltage detection circuit 21 is equal to or higher than the high voltage determination threshold Vth3. As a result of the determination, when the inverter voltage is less than the high voltage determination threshold Vth3, the control unit 5 ends the series of diagnostic processes. On the other hand, when the inverter voltage is equal to or higher than the high voltage determination threshold Vth3, the control unit 5 advances the diagnosis process to the process of step S33. As the high voltage determination threshold Vth3, for example, a voltage value that is not less than the maximum value of the control voltage of the electric motor 3 and less than the maximum value of the withstand voltage value of the inverter 2 can be exemplified.

  In the process of step S33, the control unit 5 determines whether or not the operating state of the switching circuit 23 is an open state. As a result of the determination, when the operating state of the switching circuit 23 is an open state, the control unit 5 advances the diagnosis process to the process of step S34. On the other hand, when the operation state of the switching circuit 23 is the closed state, the control unit 5 advances the diagnosis process to the process of step S37.

  In the process of step S34, the control unit 5 measures the current I21 flowing through the bypass resistor circuit R1 when the switching circuit 23 is in the open state by the current detection circuit 24 (time T = T1 shown in FIG. 10). Thereby, the process of step S34 is completed, and the diagnostic process proceeds to the process of step S35.

  In the process of step S35, the control unit 5 determines whether or not the current I21 measured by the process of step S34 is greater than a predetermined determination threshold value Ith1. As a result of the determination, if the current I21 is larger than the predetermined determination threshold value Ith1, the control unit 5 advances the diagnosis process to the process of step S36. On the other hand, when the current I21 is equal to or smaller than the predetermined determination threshold value Ith1, the control unit 5 determines that the inverter protection device 4 is operating normally, and ends the series of diagnostic processes. The determination threshold value Ith1 can be exemplified by a current value in a state where no current flows through the bypass resistor circuit R1.

  In the process of step S36, the control unit 5 determines that the inverter protection device 4 is operating abnormally because the switch circuit 23 is energized even though the operating state of the switching circuit 23 is open, and the inverter 2 and the By stopping the control of the magnetic coil L, the control of the generator 1 is stopped and the operation of the electric motor 3 is stopped. Further, when the inverter voltage becomes high, the high voltage detection circuit 22 outputs a signal for closing the operation state of the switching circuit 23 (time T = T2 shown in FIG. 10). Thereby, the process of step S36 is completed and a series of diagnostic processes are complete | finished.

  In the process of step S37, the control unit 5 measures the current I22 flowing through the bypass resistor circuit R1 when the switching circuit 23 is in the closed state by the current detection circuit 24 (time T = T3 shown in FIG. 10). Thereby, the process of step S37 is completed and the diagnostic process proceeds to the process of step S38.

  In the process of step S38, the control unit 5 determines whether or not the current I22 measured by the process of step S37 is greater than or equal to a predetermined determination threshold value Ith2. If the current I21 is greater than or equal to the predetermined determination threshold value Ith2 as a result of determination, the control unit 5 determines that the inverter protection device 4 is operating normally, and ends a series of diagnostic processes. On the other hand, if the current I21 is less than the predetermined determination threshold value Ith2, the control unit 5 advances the diagnostic process to the process of step S39. Generally, the generated power of the generator 3 is always constant when the internal combustion engine drives the generator 1 at the number of revolutions when idling and the field control of the field coil L by the control unit 5 is stopped. Therefore, the determination threshold value Ith2 is set to a predetermined voltage value equal to or less than the current value determined by the constant power and the resistance value of the bypass resistor circuit R1.

  In the process of step S39, when the control unit 5 is operating abnormally, the inverter protection device 4 is operating abnormally because the power is not consumed by the bypass resistor circuit R1 even though the operating state of the switching circuit 23 is closed. The control of the generator 1 is stopped by stopping the control of the inverter 2 and the field coil L, and the operation of the electric motor 3 is stopped. Thereby, the process of step S39 is completed and a series of diagnostic processes are completed.

  As is apparent from the above description, in the vehicle drive device according to the fourth embodiment of the present invention, the control unit 5 detects the current flowing through the bypass resistor circuit R1 when the inverter protection device 4 is operating. Since it is diagnosed whether the inverter protection device 4 operates normally by comparing with a predetermined determination threshold value, the inverter protection device can be operated even when a high voltage is applied to the inverter 2 and the inverter protection device 4 operates. Whether or not 4 operates normally can be diagnosed. In addition, the vehicle drive device of this embodiment can be used together with the vehicle drive device of 2nd Embodiment, or can each be used independently.

[Vehicle configuration]
The vehicle drive apparatus of the said embodiment is applicable to a hybrid vehicle as shown, for example in FIG. In this hybrid vehicle, as shown in FIG. 11, one main drive wheel 42 of the front and rear wheels is rotationally driven by the engine 41 of the internal combustion engine, and the slave drive wheel 44 behind the front and rear wheels is selectively rotationally driven by the motor 43. Is done. That is, the power obtained by the engine 41 is transmitted to the axle of the main drive wheel 42 via the engine side clutch 45, the transmission 46, and the differential gear 47, and the main drive wheel 42 attached to the wheel is rotationally driven. . On the other hand, the rotational driving force obtained by the motor 43 is selectively transmitted to the axle on the driven wheel 44 side through the rotational speed sensor 48, the absorbing member 49, the motor side clutch 50, and the differential gear 51, and is attached to the axle. The driven driven wheels 44 are selectively driven to rotate. Therefore, the vehicle is driven four-wheels when the motor-side clutch 50 is engaged, while the vehicle is driven two-wheels when the motor-side clutch 50 is not engaged.

  The rotation speed sensor 48 measures the rotation speed of the motor 43, applies the measured rotation speed to a motor control unit 53 and a vehicle control unit 55, which will be described later, and is used when calculating the rotation speed (ωm) of the motor 43. The absorbing member 49 is constituted by a spring or the like, for example, and alleviates the fastening impact when the motor side clutch 50 is fastened.

  A generator 52 is connected to the engine 41 via a belt or the like. The generator 52 is rotationally driven by the power obtained by the engine 41 and generates desired DC power under the control of the vehicle control unit 55. The motor 43 is provided with a temperature sensor (not shown) that measures the temperature of the motor 43, and the motor temperature measured by this temperature sensor is given to the motor control unit 53 and the vehicle control unit 55.

  The motor control unit 53 includes a drive unit 54 composed of an inverter that converts DC power obtained by the generator 52 into AC power supplied to the motor 43, and is a motor rotation speed and temperature sensor measured by the rotation speed sensor 48. The measured motor temperature and the required torque (τ) required for the motor 43 are input, and the motor 43 is driven and controlled under the control of these values and the vehicle control unit 55. The required torque required for the motor 43 is calculated as a value obtained by subtracting the torque required for the engine 41 from the torque of the entire vehicle determined according to the depression amount of the accelerator pedal and the throttle opening.

  The vehicle control unit 55 functions as a control center for controlling the operation of the vehicle, and is, for example, a microcomputer equipped with a CPU, a storage device, an input / output device, etc. necessary for a computer that controls various operation processes based on a program. Realized. The vehicle control unit 55 reads signals from a rotation speed sensor 48, a temperature sensor of the motor 43, and a sensor (not shown) that collects information necessary for driving the vehicle, and previously stores various signals read therein. Based on the control logic (program), a command is sent to the components of the hybrid vehicle including the motor side clutch 50, the generator 52, and the motor control unit 53, and all operations necessary for driving / stopping the vehicle are integrated and managed. And control.

  As mentioned above, although embodiment which applied the invention made | formed by this inventor was demonstrated, this invention is not limited with the description and drawing which make a part of indication of this invention by this embodiment. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

  The present invention can be applied to a vehicle drive device that drives a vehicle by converting the power generated by the generator into AC power by an inverter and supplying the AC power to the motor of the vehicle.

1 is a block diagram illustrating a configuration of a vehicle drive device according to a first embodiment of the present invention. It is a flowchart figure which shows the flow of the inverter protection function diagnostic process used as the 1st Embodiment of this invention. It is a wave form diagram which shows the time change of the inverter voltage at the time of performing the inverter protection function diagnostic process shown in FIG. It is a block diagram which shows the structure of the vehicle drive device used as the 2nd Embodiment of this invention. It is a flowchart figure which shows the flow of the inverter protection function diagnostic process used as the 2nd Embodiment of this invention. It is a wave form diagram which shows the time change of the electric current value which flows into the bypass resistance circuit at the time of performing the inverter protection function diagnostic process shown in FIG. It is a flowchart figure which shows the flow of the inverter protection function diagnostic process used as the 3rd Embodiment of this invention. It is a wave form diagram which shows the time change of the inverter voltage at the time of performing the inverter protection function diagnostic process shown in FIG. It is a flowchart figure which shows the flow of the inverter protection function diagnostic process used as the 4th Embodiment of this invention. FIG. 10 is a waveform diagram showing a change over time in the value of the current flowing through the bypass resistor circuit when the inverter protection function diagnosis process shown in FIG. 9 is being executed. 1 is a block diagram showing a configuration of a hybrid vehicle to which a vehicle drive device according to the present invention is applied.

Explanation of symbols

1: Generator 2: Motor drive inverter circuit 3: Motor 4: Inverter protection device 5: Control unit 11: Permanent magnet 12: Power source 21: Inverter voltage detection circuit 22: High voltage detection circuit 23: Switching circuit 24: Current detection Circuit L: Field coil R1: Bypass resistance circuit

Claims (6)

A vehicle drive device that drives a vehicle by converting the generated power of a generator driven by an internal combustion engine of the vehicle into AC power by an inverter and supplying the AC power to the motor of the vehicle,
Inverter protection means disposed between the generator and the inverter, and controls so that an overvoltage is not applied to the inverter by passing a current through the bypass resistor circuit when a voltage higher than a predetermined voltage is applied to the inverter;
Inverter voltage detecting means for detecting a voltage applied to the inverter;
A vehicle drive apparatus comprising: a diagnosis unit that diagnoses an operation state of the inverter protection unit based on a voltage value detected by the inverter voltage detection unit. In the vehicle drive device according to claim 1,
An operating means for operating the inverter protection means under a predetermined condition;
The diagnosis means detects the voltage value detected by the inverter voltage detection means when the inverter protection means is not operated by the operation means, and detects the inverter voltage when the inverter protection means is operated by the operation means. A vehicle drive apparatus characterized by diagnosing the operating state of the inverter protection means by comparing with a voltage value detected by the means.   3. The vehicle drive device according to claim 1, wherein the diagnosis unit diagnoses an operation state of the inverter protection unit when a voltage value detected by the inverter voltage detection unit is a predetermined value or more. The vehicle drive device characterized by these. A vehicle drive device that drives a vehicle by converting the generated power of a generator driven by an internal combustion engine of the vehicle into AC power by an inverter and supplying the AC power to the motor of the vehicle,
Inverter protection means disposed between the generator and the inverter, and controls so that an overvoltage is not applied to the inverter by passing a current through the bypass resistor circuit when a voltage higher than a predetermined voltage is applied to the inverter;
Current detecting means for detecting a current flowing in the bypass resistor circuit;
A vehicle drive apparatus comprising: a diagnosis unit that diagnoses an operation state of the inverter protection unit based on a current value detected by the current detection unit. The vehicle drive device according to claim 4,
An operating means for operating the inverter protection means under a predetermined condition;
The diagnosis means detects the current value detected by the current detection means when the inverter protection means is not operated by the operation means and the current detection means when the inverter protection means is operated by the operation means. A vehicle drive device characterized by diagnosing the operating state of the inverter protection means by comparing the measured current value with a predetermined threshold value. In the vehicle drive device according to claim 4 or 5,
Inverter voltage detection means for detecting the voltage applied to the inverter,
The vehicle drive apparatus characterized in that the diagnosis means diagnoses an operation state of the inverter protection means when the voltage value detected by the inverter voltage detection means is equal to or greater than a predetermined value.

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