JP7156260B2 - Inverter controller - Google Patents

Description

The present invention relates to an inverter control device.

Patent Literature 1 discloses a method of releasing a clutch between a motor and driving wheels as fail-safe control when one phase of an inverter is short-circuited.

Japanese Patent Application Laid-Open No. 2006-111260

In the method disclosed in Patent Document 1, it takes time to release the clutch after an inverter abnormality (single-phase short circuit) occurs, so there is room for improvement in stabilizing the vehicle more quickly.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inverter control apparatus capable of stabilizing a vehicle at an early stage.

In order to solve the above-described problems and achieve the object, an inverter control device according to the present invention includes an inverter, an electric motor, driving force transmission means provided between the electric motor and drive wheels, and a control unit. , when the control unit detects an abnormality in the inverter, it short-circuits the three phases of the inverter, and cuts off the driving force transmission by the driving force transmission means after the rotation speed of the electric motor becomes equal to or less than a predetermined rotation speed.

As a result, when the inverter control device according to the present invention detects an abnormality in the inverter, the inverter is first short-circuited in three phases, and after the number of revolutions of the electric motor becomes equal to or less than the predetermined number of revolutions, the driving force is transmitted. Cut off.

According to the inverter control device according to the present invention, when an abnormality of the inverter is detected, it is possible to avoid a state in which the drive wheels are rotated together by interrupting the driving force transmission. Overcharging and sudden braking can be suppressed. In addition, the vehicle can be quickly stabilized by performing a viable three-phase short-circuit earlier than cutting off the transmission of the driving force and then cutting off the transmission of the driving force.

FIG. 1 is a diagram schematically showing the configuration of a vehicle to which an inverter control device according to an embodiment of the invention is applied. FIG. 2 is a flow chart showing a first control method by the inverter control device according to the embodiment of the present invention. FIG. 3 is a flow chart showing a second control method by the inverter control device according to the embodiment of the present invention. FIG. 4 is a flow chart showing a third control method by the inverter control device according to the embodiment of the present invention.

An inverter control device according to an embodiment of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment. In addition, components in the following embodiments include components that can be easily replaced by those skilled in the art, or components that are substantially the same.

A configuration of an inverter control device according to an embodiment of the present invention will be described with reference to FIG. A vehicle 1 to which the inverter control device according to the present embodiment is applied includes an engine 10, a generator 20, a silent chain 30, a rectifier 40, an inverter 50, an electric motor 60, driving force transmission means 70, An axle 80 , drive wheels 81 , a power storage device 90 , and an ECU (Electronic Control Unit) 100 are provided.

The vehicle 1 does not use the engine 10 as a driving force source for traveling, but uses the generator 20 as a power source. The vehicle 1 has, for example, a series hybrid configuration, and the electric motor 60 is driven mainly by the electric power from the generator 20 to perform EV (Electric Vehicle) running using the electric motor 60 as a driving force source for running. conduct.

The engine 10 is an internal combustion engine such as a gasoline engine or a diesel engine. The generator 20 is a rotating electrical machine used as a motor for power generation. The silent chain 30 is a metal chain that is an endless power transmission element, and is wound around a pair of pulleys (not shown) provided on the output shaft 11 of the engine 10 and the input shaft 21 of the generator 20, respectively. The endless power transmission element is not limited to the silent chain 30. For example, other metal chains (bush chain, roller chain, etc.), rubber belts (flat belt, V belt, toothed belt, etc.), A metal belt or the like may be used.

Power output from the output shaft 11 of the engine 10 is transmitted to the input shaft 21 of the generator 20 via the silent chain 30, and the generator 20 is driven to generate power. The electric motor 60 is a rotary electric machine mainly used as a motor for running the vehicle, and uses a three-phase AC motor. Electric power sources for the electric motor 60 are a power storage device 90 such as a battery and a capacitor, and the generator 20 . Electric power from power storage device 90 is converted into three-phase alternating current by inverter 50 and supplied to electric motor 60 . Electric power from generator 20 is rectified by rectifier 40 , converted to three-phase alternating current by inverter 50 , and supplied to electric motor 60 .

In vehicle 1 , electric power from at least one of power storage device 90 and generator 20 is used to drive electric motor 60 . The driving force from the electric motor 60 is transmitted to the driving wheels 81 via the driving force transmission means 70, the axle 80, etc., and the driving wheels 81 are rotationally driven, so that the vehicle 1 travels. Also, the power storage device 90 can be charged with regenerated power from the electric motor 60 .

The driving force transmission means 70 is means for transmitting the driving force of the electric motor 60 to the drive wheels 81 and is provided between the electric motor 60 and the drive wheels 81 . The driving force transmission means 70 has at least a transmission and a differential gear. Further, the driving force transmission means 70 may include a clutch within the transmission or separately from the transmission as required. The driving force transmission means 70 can cut off the transmission of the driving force to the drive wheels 81 by the transmission when the clutch is not provided, and the transmission of the driving force to the drive wheels 81 by the clutch when the clutch is provided. can be blocked.

The ECU 100 is physically composed of an electronic circuit mainly composed of a well-known microcomputer including interfaces such as a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and input/output. . These functions of the ECU 100 are realized by loading an application program held in the ROM into the RAM and executing it by the CPU.

The ECU 100 also includes a rotation speed sensor 110 for detecting the rotation speed of the engine 10 , a rotation angle sensor 111 for detecting the rotation angle of the engine 10 , a resolver angle sensor 120 for detecting the resolver angle of the generator 20 , and the rotation speed of the electric motor 60 . Various detected values are input from a rotational speed sensor 160 that detects the number of revolutions, an SOC detection sensor 190 that detects the SOC (State of Charge) of the power storage device 90, and the like.

Here, in a configuration in which there is no boost converter and a transmission or a clutch is provided in the rear stage of the electric motor 60, as in the vehicle 1, when there is an abnormality in the inverter 50 such as one-phase short circuit or one-phase open, Even if the fail-safe control by the inverter 50 as described above is performed, it may not be possible to cope with the risk of overcharging or sudden braking due to the back electromotive force. Therefore, in the inverter control device according to the present embodiment, the drive system performs fail-safe control such as setting the gear stage to neutral and disengaging the clutch.

ECU 100 performs one of the following as fail-safe control when an abnormality of inverter 50 is detected.
(1) Shut down the inverter 50 after setting the gear stage to neutral.
(2) Cut power supply to the power storage device 90 or the like.
(3) Three phases of the inverter 50 are short-circuited, and after the number of rotations of the electric motor 60 becomes equal to or less than a predetermined number of rotations, the driving force transmission by the driving force transmission means 70 is interrupted.

(First control method)
A first control method performed by the inverter control device according to the present embodiment will be described below with reference to FIG. First, the ECU 100 determines whether or not an abnormality has occurred in the inverter 50 (step S1). A method for detecting an abnormality of the inverter 50 is not particularly limited, but the abnormality can be detected using, for example, a current sensor (not shown) provided in the inverter 50 . Moreover, as an abnormality of the inverter 50, one-phase short-circuit, one-phase open, and the like can be cited.

When the ECU 100 determines that the inverter 50 is abnormal (Yes in step S1), the ECU 100 sets the gear stage to neutral (step S2). Here, "setting the gear stage to neutral" means that the input and output of the transmission of the driving force transmission means 70 are disconnected. There are a plurality of methods for setting the gear stage to neutral, for example, a method of setting the gear stage of the transmission to neutral, a method of adjusting the number of rotations during gear shifting by the transmission, and a method of adjusting the clutch provided in the transmission of the driving force transmission means 70. A method of releasing, a method of releasing a clutch provided in the driving force transmission means 70 separately from the transmission, and the like.

Subsequently, the ECU 100 shuts down the inverter 50 (step S3) and ends this flow. Here, "shutdown" means shutting off all phases of the inverter 50 . If it is determined in step S1 that an abnormality has not occurred in inverter 50 (No in step S1), ECU 100 causes vehicle 1 to run normally (step S4).

(Second control method)
A second control method performed by the inverter control device according to the present embodiment will be described below with reference to FIG. First, the ECU 100 determines whether or not a short circuit has occurred in the inverter 50 (step S11). A method for detecting a short-circuit failure of the inverter 50 is not particularly limited, but the short-circuit failure can be detected using, for example, a current sensor (not shown) provided in the inverter 50 .

When the ECU 100 determines that a short-circuit failure has occurred in the inverter 50 (Yes in step S11), it determines whether or not the field-weakening control is impossible (step S12). Here, "field weakening control" means control for weakening the field current and increasing the rotational speed of the electric motor 60. As shown in FIG.

When the ECU 100 determines that the weak field control is impossible (Yes in step S12), it determines whether or not the mechanical neutral control is impossible (step S13). Here, "mechanical neutral control" means to mechanically create a neutral state, and specifically means to set the gear stage of the transmission to neutral as described above. .

When the ECU 100 determines that the mechanical neutral control is impossible (Yes in step S13), it determines whether or not the three-phase short circuit of the inverter 50 is impossible (step S14). When the ECU 100 determines that the three-phase short-circuiting of the inverter 50 is impossible (Yes in step S14), the ECU 100 performs a procedure to stop the electric motor 60 (step S15), and terminates this process. It should be noted that “stopping action” means cutting off the energization of power storage device 90 .

If it is determined in step S11 that the inverter 50 does not have a short-circuit failure (No in step S11), the ECU 100 causes the vehicle 1 to run normally (step S16). If it is determined in step S12 that field weakening control is not possible (No in step S12), the ECU 100 performs field weakening control (step S17). If it is determined in step S13 that mechanical neutral control is not possible (No in step S13), the ECU 100 performs mechanical neutral control (step S18). Further, when it is determined in step S14 that the three-phase short circuit of the inverter 50 is not possible (No in step S14), the ECU 100 performs the three-phase short circuit of the inverter 50 (step S19).

(Third control method)
A third control method performed by the inverter control device according to the present embodiment will be described below with reference to FIG. First, the ECU 100 determines whether or not a short circuit has occurred in the inverter 50 (step S21). A method for detecting a short-circuit failure of the inverter 50 is not particularly limited, but the short-circuit failure can be detected using, for example, a current sensor (not shown) provided in the inverter 50 .

When the ECU 100 determines that the inverter 50 has a short-circuit failure (Yes in step S21), the inverter 50 is short-circuited in three phases (step S22). Subsequently, the ECU 100 determines whether or not the rotation speed of the electric motor 60 is equal to or less than a predetermined rotation speed (step S23). When the ECU 100 determines that the number of revolutions of the electric motor 60 is equal to or less than the predetermined number of revolutions (Yes in step S23), the ECU 100 sets the gear stage to neutral (step S24), and terminates this process.

If it is determined in step S21 that the inverter 50 does not have a short-circuit failure (No in step S21), the ECU 100 terminates this process. Further, when it is determined in step S23 that the rotation speed of the electric motor 60 is not equal to or lower than the predetermined rotation speed (No in step S23), the ECU 100 returns to step S23.

Since it takes time to mechanically create the neutral state, in the third control, the three phases of the inverter 50 are first short-circuited. In the three-phase short-circuit state, a torque shock occurs on the side of the electric motor 60 with a low rotational speed. to neutral.

According to the inverter control device as described above, when an abnormality of the inverter 50 is detected, the transmission of the driving force is interrupted, thereby avoiding a state in which the drive wheels 81 are rotated together. Overcharging and sudden braking due to electromotive force can be suppressed. Further, as in the third control described above, when an abnormality of the inverter 50 is detected, a feasible three-phase short-circuit is performed earlier than the drive force transmission is interrupted, and then the drive force transmission is interrupted. As a result, the vehicle 1 can be stabilized at an early stage.

Although the inverter control device according to the present invention has been specifically described above in terms of the modes for carrying out the invention, the gist of the present invention is not limited to these descriptions, and is set forth in the scope of claims. should be broadly interpreted on the basis of Further, it goes without saying that various changes and alterations based on these descriptions are also included in the gist of the present invention.

For example, in the above-described embodiment, the vehicle 1 has been described assuming that it is a hybrid vehicle (HV), but the vehicle 1 may be an electric vehicle (EV).

1 Vehicle 10 Engine 20 Generator 30 Silent Chain 40 Rectifier 50 Inverter 60 Electric Motor 70 Driving Force Transmission Means 80 Axle 81 Driving Wheel 90 Power Storage Device 100 ECU
110 rotation speed sensor 111 rotation angle sensor 120 resolver angle sensor 160 rotation speed sensor 190 SOC detection sensor

Claims (1)

an inverter;
an electric motor;
a driving force transmission means provided between the electric motor and the drive wheels;
a control unit;
with
When an abnormality of the inverter is detected, the control unit short-circuits the three phases of the inverter, and after the number of revolutions of the electric motor becomes equal to or less than a predetermined number of revolutions, cuts off the driving force transmission by the driving force transmission means.
Inverter controller.

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