JP6967750B2 - Motor control device and control method of motor control device - Google Patents

Description

This disclosure relates to a motor control device and a control method for the motor control device.

Conventionally, a motor control device that controls a motor by the electric power of a DC power source is known. As an example of such a motor control device, Patent Document 1 discloses an electric vehicle of an electric vehicle that uses a battery as a power source and drives a permanent magnet type synchronous motor for driving a vehicle via a voltage type inverter. In the electric system of this electric vehicle, when an abnormality occurs such that the DC circuit from the battery to the inverter is opened while the vehicle is running, the switching elements of the upper arm or the lower arm of the inverter are turned on all at once for synchronization. The input terminal of the electric motor is short-circuited to stop the power supply from the inverter.

Japanese Unexamined Patent Publication No. 9-47055

However, the electric system of Patent Document 1 has room for improvement as a motor control device.

For example, in the electric system of Patent Document 1, if an abnormality occurs and the switching element of the upper arm or the lower arm of the inverter is controlled to be turned on all at once, the rotational speed of the synchronous motor decreases. The regenerative torque acting on the synchronous motor may cause the rotational speed of the synchronous motor to drop sharply. It is conceivable to perform control to turn off all switching elements of the inverter when an abnormality occurs. However, if the rotation speed of the synchronous motor increases while the control is performed to turn off all the switching elements of the inverter due to an abnormality, the power is regenerated from the synchronous motor to the battery side via the inverter. The power line connecting the inverter and the inverter may become overvoltage (for example, a voltage exceeding the legally regulated voltage). As described above, in the electric system of Patent Document 1, it is difficult to suppress both the sudden deceleration of the synchronous motor and the overvoltage of the power line connecting the power supply and the inverter.

Therefore, in the present disclosure, a motor control device capable of further improvement is provided.

This disclosure relates to a motor control device that controls a three-phase AC type motor by the power of a DC power source, and the motor control device includes three output lines connected to three input terminals of the motor and the DC power supply. Three high-side switching elements connected to the power supply line connected to the positive side, and three connected to the ground line connected to the negative side of the DC power supply and the three output lines. It includes an inverter having a low-side switching element, a sensor for detecting information used for controlling the switching operation of the inverter, and a control unit. The control unit determines an abnormality in at least one of the DC power supply, the motor, the inverter, and the sensor, and the information detected by the sensor until the abnormality determination determines that there is an abnormality. The normal control for controlling the switching operation of the inverter is performed based on the above three high-side switching according to the torque acting on the motor in the abnormality continuation period after the abnormality determination determines that there is an abnormality. Three-phase short-circuit control and the three-phase short-circuit control in which one of the high-side switching element group consisting of the elements and the low-side switching element group consisting of the three low-side switching elements is turned on and the other switching element group is turned off. Either one of the high-side switching element group and the fully open control for turning off all of the low-side switching element group is performed. The control unit further includes an abnormality determination unit that determines an abnormality with respect to the DC power supply, the motor, the inverter, and the sensor, and the DC power supply, the motor, the inverter, and the sensor by the abnormality determination unit. It has a normal control unit and an abnormality control unit that control the switching operation of the inverter based on the information detected by the sensor until at least one of them is determined to be abnormal. The abnormality control unit has the three-phase short circuit according to the operating state of the motor before the DC power supply, the motor, the inverter, and at least one of the sensors are determined to be abnormal by the abnormality determination unit. When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality control selection unit that selects either control or the fully open control, and the abnormality determination unit. It has an abnormality control execution unit that performs control selected by the abnormality control selection unit among the three-phase short circuit control and the fully open control.
Further, this disclosure is a motor control device that controls a three-phase AC type motor by the power of a DC power supply, and is used for three output lines connected to three input terminals of the motor and a positive electrode of the DC power supply. Three high-side switching elements connected to each of the connected power supply lines and three low-side switching elements connected to each of the three output lines and the ground wire connected to the negative electrode of the DC power supply. An inverter having an element, a sensor that detects information used for controlling the switching operation of the inverter, an abnormality determination unit that determines an abnormality in the DC power supply, the motor, the inverter, and the sensor, and the above. Normal control that controls the switching operation of the inverter based on the information detected by the sensor until at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination unit. When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the unit and the abnormality determination unit, the three high-side switching elements are determined according to the operating state of the motor. Three-phase short-circuit control and the high are that one of the high-side switching element group consisting of the high-side switching element group and the low-side switching element group consisting of the three low-side switching elements is turned on and the other switching element group is turned off. It is provided with an abnormality control unit that selects and performs either a side switching element group or a fully open control that turns off all of the low side switching element group, and the abnormality control unit is the DC power supply by the abnormality determination unit. An abnormality in which either the three-phase short-circuit control or the fully open control is selected according to the operating state of the motor before at least one of the motor, the inverter, and the sensor is determined to be abnormal. When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the control selection unit and the abnormality determination unit, the abnormality among the three-phase short circuit control and the fully open control is performed. It has an abnormality control execution unit that performs control selected by the control selection unit.

Further, this disclosure also describes three high-side switchings connected between three output lines connected to three input terminals of a three-phase AC type motor and a power supply line connected to the positive electrode of a DC power supply. An inverter having an element, three low-side switching elements connected between the three output lines and a ground wire connected to the negative electrode of the DC power supply, and information used for controlling the switching operation of the inverter. Regarding the control method of the motor control device including the sensor for detecting the above, the control method of the motor control device is an abnormality in which an abnormality is determined for at least one of the DC power supply, the motor, the inverter, and the sensor. It is determined that there is an abnormality in the determination step, the normal control step that controls the switching operation of the inverter based on the information detected by the sensor until it is determined that there is an abnormality by the abnormality determination step, and the abnormality determination step. One of the high-side switching element group consisting of the three high-side switching elements and the low-side switching element group consisting of the three low-side switching elements according to the torque acting on the motor during the abnormal continuation period after the determination. Either three-phase short-circuit control that turns on the switching element group and turns off the other switching element group, or full-open control that turns off the high-side switching element group and the low-side switching element group. Includes anomalous continuation response steps to do one. The control method of the motor control device further includes an abnormality control step, and the abnormality control step determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal by the abnormality determination step. The DC power supply, the motor, and the inverter are selected by the abnormality control selection step of selecting one of the three-phase short-circuit control and the fully open control according to the operating state of the motor, and the abnormality determination step. And an abnormality control execution step of performing the control selected by the abnormality control selection step among the three-phase short-circuit control and the fully open control when at least one of the sensors is determined to be abnormal. ..
Further, this disclosure also describes three high-side switchings connected between three output lines connected to each of the three input terminals of a three-phase AC type motor and a power supply line connected to the positive electrode of a DC power supply. An inverter having an element, three low-side switching elements connected between the three output lines and a ground wire connected to the negative electrode of the DC power supply, and information used for controlling the switching operation of the inverter. It is a control method of a motor control device provided with a sensor for detecting a DC power source, that is, an abnormality determination step for determining an abnormality with respect to the DC power supply, the motor, the inverter, and the sensor, and the DC in the abnormality determination step. When at least one of the power supply, the motor, the inverter, and the sensor is determined to be abnormal, the high-side switching element group composed of the three high-side switching elements and the said are according to the operating state of the motor. Three-phase short-circuit control that turns one switching element group on and the other switching element group off from the low-side switching element group consisting of three low-side switching elements, the high-side switching element group, and the low-side switching element. The abnormality control step includes an abnormality control step in which one of the fully open controls for turning off the entire group is selected, and the abnormality control step includes the DC power supply, the motor, the inverter, and the above in the abnormality determination step. Before it is determined that at least one of the sensors is abnormal, an abnormality control selection step of selecting one of the three-phase short circuit control and the fully open control according to the operating state of the motor, and the abnormality determination. When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the step, it is selected by the abnormality control selection step among the three-phase short circuit control and the fully open control. Includes anomalous control execution steps for control.

The motor control device and the control method of the motor control device according to one aspect of the present disclosure can be further improved. For example, both sudden deceleration of the motor and overvoltage of the power line connecting the DC power supply and the inverter can be effectively suppressed.

It is a block diagram illustrating the configuration of the motor control device according to the first embodiment. It is a block diagram which illustrates the structure of the switching control part. It is a graph which illustrates the relationship between torque and rotation speed in three-phase short circuit control. It is a graph which exemplifies the relationship between the torque and the rotation speed in the fully open control. It is a flowchart which illustrates the switching operation of the field weakening control. It is a flowchart which exemplifies an abnormality occurrence response operation. It is a flowchart which exemplifies the abnormality continuation correspondence operation. It is a block diagram illustrating the configuration of the motor control device according to the second embodiment. It is a block diagram illustrating the configuration of the motor control device according to the third embodiment. It is a flowchart illustrating the details of three-phase short circuit control. It is a block diagram illustrating the configuration of the motor control device according to the fourth embodiment. It is a flowchart which illustrates the operation by the abnormality control selection part of Embodiment 4. It is a flowchart which illustrates the operation by the abnormality control execution part of Embodiment 4. It is a block diagram illustrating the configuration of the motor control device according to the fifth embodiment.

The motor control device according to one aspect of the present disclosure is a motor control device that controls a three-phase AC type motor by the electric power of a DC power source, and has three output lines connected to three input terminals of the motor. Three high-side switching elements connected to the power supply line connected to the positive side of the DC power supply, and a ground line connected to the three output lines and the negative side of the DC power supply, respectively. It includes an inverter having three low-side switching elements, a sensor for detecting information used for controlling the switching operation of the inverter, and a control unit. The control unit determines an abnormality in at least one of the DC power supply, the motor, the inverter, and the sensor, and the information detected by the sensor until the abnormality determination determines that there is an abnormality. The normal control for controlling the switching operation of the inverter is performed based on the above three high-side switching according to the torque acting on the motor in the abnormality continuation period after the abnormality determination determines that there is an abnormality. Three-phase short-circuit control and the three-phase short-circuit control in which one of the high-side switching element group consisting of the elements and the low-side switching element group consisting of the three low-side switching elements is turned on and the other switching element group is turned off. Either one of the high-side switching element group and the fully open control for turning off all of the low-side switching element group is performed.

As a result, by performing either three-phase short-circuit control or full-open control according to the torque acting on the motor during the abnormal continuation period, the motor is suddenly decelerated and the overvoltage of the power line connecting the DC power supply and the inverter is overvoltage. Both can be effectively suppressed.

Further, the control unit includes an abnormality determination unit that determines an abnormality in at least one of the DC power supply, the motor, the inverter, and the sensor, and the normal control, the three-phase short circuit control, and the fully open control. The switching control unit that performs the above operation and the switching control unit perform the normal control until the abnormality determination unit determines that there is an abnormality, and the three-phase according to the torque acting on the motor during the abnormality continuation period. It may have an operation control unit that causes the switching control unit to perform either short-circuit control or full-open control.

As a result, both the sudden deceleration of the motor and the overvoltage of the power line connecting the DC power supply and the inverter can be effectively suppressed by the specific interlocking of the abnormality determination unit, the switching control unit, and the operation control unit in the control unit. Can be done.

Further, the abnormality determination unit is composed of hardware separate from the switching control unit and the operation control unit, and it is said that at least one of the DC power supply, the motor, the inverter, and the sensor has an abnormality. If it is determined, an abnormality detection signal may be output to the operation control unit.

As a result, by configuring the abnormality determination unit by hardware, the abnormality determination in the abnormality determination unit can be performed more quickly than in the case where the abnormality determination unit is configured by software.

Further, the operation control unit is configured by hardware separate from the switching control unit, and outputs a control signal for performing any one of the normal control, the three-phase short circuit control, and the fully open control. It may be output to the switching control unit.

As a result, by configuring the motion control unit by hardware, it is possible to control the switching control unit by the motion control unit more quickly than when the motion control unit is configured by software.

Further, the control unit ends the three-phase short-circuit control when the torque acting on the motor falls below a predetermined first torque threshold when the three-phase short-circuit control is performed during the abnormal continuation period. Then, when the full-open control is started and the torque acting on the motor exceeds a predetermined second torque threshold when the full-open control is performed, the full-open control is terminated and the three-phase is terminated. Short circuit control may be started.

As a result, by switching between three-phase short-circuit control and full-open control according to the torque acting on the motor during the abnormal continuation period, sudden deceleration of the motor and overvoltage of the power line connecting the DC power supply and the inverter can be achieved. Both can be effectively suppressed.

Further, the sensor includes a current sensor for detecting the phase current flowing through the motor and a magnetic pole position sensor for detecting the magnetic pole position of the motor, and the control unit includes the phase current detected by the current sensor. The torque acting on the motor may be acquired based on the magnetic pole position detected by the magnetic pole position sensor.

This eliminates the need to separately provide a torque sensor that detects the torque acting on the motor.

Further, in the normal control, the control unit performs field weakening control on the motor according to the rotation speed of the motor, and when it is determined by the abnormality determination that there is an abnormality, the field weakening control on the motor is performed. Either the three-phase short-circuit control or the fully open control may be performed depending on whether or not the motor is implemented and at least one of the rotation speeds of the motor.

As a result, it is possible to appropriately perform control according to at least one of the three-phase short-circuit control and the fully open control, which is the presence / absence of field weakening control for the motor and the rotation speed of the motor.

Further, the control unit includes an abnormality determination unit that determines an abnormality with respect to the DC power supply, the motor, the inverter, and the sensor, and the DC power supply, the motor, the inverter, and the sensor by the abnormality determination unit. The abnormality control unit includes a normal control unit and an abnormality control unit that control the switching operation of the inverter based on the information detected by the sensor until at least one of them is determined to be abnormal. Before the DC power supply, the motor, the inverter, and at least one of the sensors are determined to be abnormal by the abnormality determination unit, the three-phase short circuit control and the full opening are performed according to the operating state of the motor. When it is determined by the abnormality control selection unit that selects one of the controls and the abnormality determination unit that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal, the three-phase short circuit control is performed. And the abnormality control execution unit that performs the control selected by the abnormality control selection unit among the fully open controls may be provided.

As a result, in addition to the effect of effectively suppressing both the sudden deceleration of the motor and the overvoltage of the power line connecting the DC power supply and the inverter during the abnormal continuation period, the motor is before the abnormality determination unit determines that there is an abnormality. Since either three-phase short-circuit control or full-open control can be selected according to the operating state of, three-phase short-circuit control or full-open control is performed when an abnormality is determined by the abnormality determination unit. It can be done quickly.

Further, the abnormality determination unit is composed of hardware separate from the normal control unit and the abnormality control unit, and it is determined that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. Then, the abnormality detection signal is output, and the normal control unit controls the switching operation of the inverter based on the information detected by the sensor until the abnormality detection signal is output by the abnormality determination unit, and the abnormality is output. When the abnormality detection signal is output by the abnormality determination unit, the control unit may select either the three-phase short circuit control or the fully open control according to the operating state of the motor.

As a result, when it is determined that there is an abnormality by the abnormality determination, the operating state of the motor (specifically, whether or not the field weakening control is performed on the motor and the rotation speed of the motor among the three-phase short-circuit control and the fully open control) are determined. Control according to at least one of them) can be appropriately performed.

Further, the abnormality determination unit determines whether or not the switching element is a short-circuit abnormality that is always on for each of the three high-side switching elements and the three low-side switching elements, and controls the abnormality. In the three-phase short-circuit control, the unit turns on the switching element group including the switching element determined to be the short-circuit abnormality by the abnormality determination unit among the high-side switching element group and the low-side switching element group. It may be configured as follows.

As a result, even when a short-circuit abnormality occurs in the six switching elements (three high-side switching elements and three low-side switching elements), the three-phase short-circuit control can be normally performed.

Further, the abnormality determination unit is configured to determine whether or not each of the three high-side switching elements and the three low-side switching elements is an open abnormality in which the switching element is always in an off state. In the three-phase short-circuit control, the abnormality control unit includes a switching element group including a switching element determined by the abnormality determination unit to be an open abnormality among the high-side switching element group and the low-side switching element group. It may be configured to be turned off.

As a result, even when an opening abnormality occurs in the six switching elements (three high-side switching elements and three low-side switching elements), the three-phase short-circuit control can be normally performed.

The motor control device according to one aspect of the present disclosure is a motor control device that controls a three-phase AC type motor by the power of a DC power source, and has three output lines connected to three input terminals of the motor. Three high-side switching elements connected to the power supply line connected to the positive side of the DC power supply, and a ground line connected to the three output lines and the negative side of the DC power supply, respectively. An abnormality is determined for the inverter having the three low-side switching elements, the sensor for detecting the information used for controlling the switching operation of the inverter, the DC power supply, the motor, the inverter, and the sensor. Switching of the inverter based on the information detected by the sensor until at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination unit and the abnormality determination unit. When it is determined by the normal control unit that controls the operation and the abnormality determination unit that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal, the operation state of the motor is determined to be abnormal. Three of the high-side switching element group consisting of three high-side switching elements and the low-side switching element group consisting of the three low-side switching elements are turned on and the other switching element group is turned off. It is provided with an abnormality control unit that selects and performs either phase short-circuit control or full-open control that turns off all of the high-side switching element group and the low-side switching element group. The abnormality control unit has the three-phase short circuit according to the operating state of the motor before the DC power supply, the motor, the inverter, and at least one of the sensors are determined to be abnormal by the abnormality determination unit. When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality control selection unit that selects either control or the fully open control, and the abnormality determination unit. It has an abnormality control execution unit that performs control selected by the abnormality control selection unit among the three-phase short circuit control and the fully open control.

As a result, one of the three-phase short-circuit control and the fully open control can be selected according to the operating state of the motor before the abnormality determination unit determines that there is an abnormality. Therefore, the abnormality determination unit can select the abnormality. When it is determined that there is, three-phase short-circuit control or full-open control can be performed quickly.

The control method of the motor control device according to one aspect of the present disclosure is between the three output lines connected to the three input terminals of the three-phase AC type motor and the power supply line connected to the positive electrode of the DC power supply. An inverter having three high-side switching elements connected to each and three low-side switching elements connected between the three output lines and the ground wire connected to the negative electrode of the DC power supply, and the inverter. It is a control method of a motor control device provided with a sensor for detecting information used for controlling the switching operation of the above, and an abnormality determination is made for at least one of the DC power supply, the motor, the inverter, and the sensor. An abnormality determination step is performed, a normal control step that controls the switching operation of the inverter based on the information detected by the sensor until an abnormality is determined by the abnormality determination step, and an abnormality determination step. In the abnormal continuation period after it is determined to be present, the high-side switching element group composed of the three high-side switching elements and the low-side switching element group composed of the three low-side switching elements are subjected to, depending on the torque acting on the motor. Three-phase short-circuit control that turns one switching element group on and the other switching element group off, and full-open control that turns off the high-side switching element group and the low-side switching element group. Includes an anomaly continuation response step in which one is performed.

As a result, by performing either three-phase short-circuit control or full-open control according to the torque acting on the motor during the abnormal continuation period, the motor is suddenly decelerated and the overvoltage of the power line connecting the DC power supply and the inverter is overvoltage. Both can be effectively suppressed.

Further, the control method of the motor control device further includes an abnormality control step, and in the abnormality control step, at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal due to the abnormality determination step. Before the determination, the abnormality control selection step of selecting one of the three-phase short-circuit control and the fully open control according to the operating state of the motor, and the DC power supply, the motor, and the said by the abnormality determination step. When it is determined that at least one of the inverter and the sensor is abnormal, the abnormality control execution step of performing the control selected by the abnormality control selection step among the three-phase short-circuit control and the fully open control is performed. Further may be included.

As a result, in addition to performing control according to the torque acting on the motor among the three-phase short-circuit control and the fully open control, three according to the operating state of the motor before it is determined that there is an abnormality by the abnormality determination step. Since either phase short-circuit control or full-open control can be selected, three-phase short-circuit control or full-open control can be quickly performed when an abnormality is determined by the abnormality determination step.

The control method of the motor control device according to one aspect of the present disclosure is between the three output lines connected to the three input terminals of the three-phase AC type motor and the power supply line connected to the positive electrode of the DC power supply. An inverter having three high-side switching elements connected to each and three low-side switching elements connected between the three output lines and the ground wire connected to the negative electrode of the DC power supply, and the inverter. This is a control method of a motor control device including a sensor for detecting information used for controlling the switching operation of the DC power supply, the motor, the inverter, and the sensor. When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal in the abnormality determination step, the three high-side switching elements are determined according to the operating state of the motor. Three-phase short-circuit control and the high are that one of the high-side switching element group consisting of the high-side switching element group and the low-side switching element group consisting of the three low-side switching elements is turned on and the other switching element group is turned off. The abnormality control step includes an abnormality control step in which one of a side switching element group and a fully open control for turning off all of the low side switching element groups is selected, and the abnormality control step is a direct current according to the abnormality determination step. Before it is determined that at least one of the power supply, the motor, the inverter, and the sensor is abnormal, either the three-phase short-circuit control or the fully open control is selected according to the operating state of the motor. Of the three-phase short circuit control and the fully open control when at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality control selection step and the abnormality determination step. An abnormality control execution step for performing the control selected by the abnormality control selection step is included.

As a result, one of the three-phase short-circuit control and the fully open control can be selected according to the operating state of the motor before the abnormality is determined by the abnormality determination step. Therefore, the abnormality is determined by the abnormality determination step. When it is determined that there is, three-phase short-circuit control or full-open control can be performed quickly.

Hereinafter, embodiments will be specifically described with reference to the drawings.

It should be noted that all of the embodiments described below are comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps, the order of steps, etc. shown in the following embodiments are examples, and are not intended to limit the present invention. Further, among the components in the following embodiments, the components not described in the independent claim indicating the highest level concept are described as arbitrary components. Further, each figure is a schematic view and is not necessarily exactly illustrated. Further, in each figure, the same components are designated by the same reference numerals.

(Embodiment 1)
FIG. 1 illustrates the configuration of the motor control device 10 according to the first embodiment. The motor control device 10 is configured to control the three-phase AC type motor 3 by the electric power of the DC power source 2. In this example, the motor 3 is configured to drive the drive wheels (not shown) of the electric vehicle. This electric vehicle is provided with a power transmission mechanism (not shown) that transmits power between the motor 3 and the drive wheels. The power transmission mechanism is composed of, for example, a differential gear or a drive shaft. The rotational force of the motor 3 is transmitted to the drive wheels via the power transmission mechanism. Similarly, the rotational force of the drive wheels is transmitted to the motor 3 via the power transmission mechanism. The motor 3 and the drive wheels of the electric vehicle may be directly connected without going through the power transmission mechanism.

Further, in this example, the motor 3 is composed of a permanent magnet motor. For example, the motor 3 is composed of an embedded magnet synchronous motor (IPMSM), a surface magnet synchronous motor (SPMSM), and the like. The motor 3 may be configured by a brushless motor. The DC power supply 2 may be composed of, for example, a lithium ion battery.

In this example, the motor control device 10 includes an inverter 11, a smoothing capacitor 12, a sensor 20, and a control unit 30.

[Inverter]
The inverter 11 is configured to convert the DC power supplied from the DC power supply 2 by the switching operation into three-phase AC power and supply the AC power to the motor 3. Specifically, the inverter 11 has three high-side switching elements (first, second, third high-side switching elements S1, S2, S3) and three low-side switching elements (first, second, third). It has low-side switching elements S4, S5, S6).

The three high-side switching elements S1 to S3 have three output lines (first, second, third output lines LOu, Lov, LOw) connected to three input terminals of the motor 3, respectively, and a positive electrode of the DC power supply 2. It is connected to each of the power supply line LP connected to. For example, the high-side switching elements S1 to S3 are composed of a field effect transistor (FET), an insulated gate bipolar transistor (IGBT), and the like. Further, the high-side switching elements S1 to S3 may be configured by using a wide bandgap semiconductor.

The three low-side switching elements S4 to S6 are connected between the three output lines LOu to LOw and the ground wire LG connected to the negative electrode of the DC power supply 2, respectively. For example, the low-side switching elements S4 to S6 are composed of a field effect transistor (FET), an insulated gate bipolar transistor (IGBT), and the like. Further, the low-side switching elements S4 to S6 may be configured by using a wide bandgap semiconductor.

In this example, a freewheeling diode is connected in parallel to each of the six switching elements S1 to S6. These freewheeling diodes may be parasitic diodes parasitic on the switching elements S1 to S6, or may be diode elements configured separately from the switching elements S1 to S6.

[Smoothing capacitor]
The smoothing capacitor 12 is connected between the power supply line LP and the ground line LG, and is configured to smooth the power supply voltage VP applied to the power supply line LP. Specifically, the smoothing capacitor 12 is configured to reduce the ripple of the power supply voltage VP and absorb the surge voltage. For example, the smoothing capacitor 12 is composed of an electrolytic capacitor and a film capacitor.

[Sensor]
The sensor 20 is configured to detect information used for controlling the switching operation of the inverter 11. In this example, the motor control device 10 includes three current sensors (first, second, third current sensors 21u, 21v, 21w) corresponding to the three output lines LOu to LOw, a magnetic pole position sensor 22, and the like. Various sensors are provided.

The three current sensors 21u to 21w are configured to detect each of the three phase currents (U-phase current iu, V-phase current iv, and W-phase current iwa) flowing through the motor 3. For example, the current sensors 21u to 21w are configured by a shunt resistor.

The magnetic pole position sensor 22 is configured to detect the magnetic pole position θe of the motor 3.

[Control unit]
The control unit 30 is configured to control the switching operation of the inverter 11 based on the information detected by the sensor 20, a control command input from the outside, and the like. For example, the control unit 30 supplies a gate signal to the arithmetic processing unit such as a CPU, a storage unit such as a memory for storing programs and information for operating the arithmetic processing unit, and switching elements S1 to S6 for switching. It is composed of a drive circuit such as a gate drive IC that controls on / off of the elements S1 to S6.

In this example, the control unit 30 includes the phase currents iu to iw detected by the current sensors 21u to 21w, the magnetic pole position θe of the motor 3 detected by the magnetic pole position sensor 22, the power supply voltage VP, and the motor 3. A torque command Te indicating a target torque (for example, a torque corresponding to the operation amount of the accelerator pedal of an electric vehicle) is input.

Further, the control unit 30 determines an abnormality in at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20. In this example, the control unit 30 makes an abnormality determination for all of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20. The abnormality determination will be described in detail later.

Further, the control unit 30 performs normal control until it is determined by the abnormality determination that there is an abnormality. In normal control, the control unit 30 controls the switching operation of the inverter 11 based on the information detected by the sensor 20. Specifically, the control unit 30 detects signals (specifically,) from various sensors such as the current sensors 21u to 21w and the magnetic pole position sensor 22 so that the torque of the motor 3 becomes the target torque indicated by the torque command Te. Controls the switching operation of the inverter 11 based on the phase currents iu to iw flowing through the three output lines LOu to LOw and the magnetic pole position θe of the motor 3 respectively.

In this example, the control unit 30 is configured to perform field weakening control on the motor 3 according to the rotation speed of the motor 3 in normal control. Specifically, in normal control, the control unit 30 performs field weakening control on the motor 3 when the rotation speed of the motor 3 exceeds a predetermined high rotation threshold, and the rotation speed of the motor 3 is high. It is configured so that the field weakening control is not performed on the motor 3 when the rotation threshold is not exceeded. The high rotation threshold is set to a rotation speed lower than the rotation speed of the motor 3 when the counter electromotive force generated by the rotation of the motor 3 becomes equal to the power supply voltage of the DC power supply 2.

In this example, the control unit 30 is configured to acquire the rotational speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. Specifically, the control unit 30 calculates the rotation speed of the motor 3 by differentiating the magnetic pole position θe detected by the magnetic pole position sensor 22.

Further, when the abnormality determination determines that there is an abnormality, the control unit 30 performs either three-phase short-circuit control or full-open control according to the operating state of the motor 3. In the three-phase short circuit control, the control unit 30 selects one of a high-side switching element group consisting of three high-side switching elements S1 to S3 and a low-side switching element group consisting of three low-side switching elements S4 to S6. Turn it on and turn the other switching element group off. In the fully open control, the control unit 30 turns off all of the high-side switching element group composed of the three high-side switching elements S1 to S3 and the low-side switching element group composed of the three low-side switching elements S4 to S6.

In this example, when the control unit 30 determines that there is an abnormality by the abnormality determination, the three-phase short-circuit control and full opening are performed according to at least one of the presence / absence of field weakening control for the motor 3 and the rotation speed of the motor 3. It is configured to do either of the controls. Specifically, the control unit 30 performs three-phase short-circuit control with respect to the motor 3 when the field weakening control for the motor 3 is performed or when the rotation speed of the motor 3 exceeds a predetermined rotation speed threshold. It is configured to perform full open control when the field weakening control is not performed and the rotation speed of the motor 3 does not exceed the rotation speed threshold. The rotation speed threshold may be the same rotation speed as the high rotation threshold (rotation speed that is a criterion for determining whether or not the field weakening control is necessary), or may be a rotation speed different from the high rotation threshold. ..

Further, the control unit 30 performs either three-phase short-circuit control or full-open control according to the torque Tet acting on the motor 3 in the period after the abnormality is determined by the abnormality determination (abnormality continuation period). conduct. Specifically, the control unit 30 performs a three-phase short circuit when the torque Tet acting on the motor 3 when the three-phase short circuit control is performed falls below a predetermined first torque threshold value Tth1 during the abnormal continuation period. The control is terminated and the full open control is started. Further, the control unit 30 ends the full-open control when the torque Tet acting on the motor 3 exceeds a predetermined second torque threshold value Tth2 when the full-open control is performed during the abnormal continuation period. Start three-phase short circuit control. The first torque threshold value Tth1 and the second torque threshold value Tth2 will be described in detail later.

In this example, the control unit 30 acquires the torque Tet acting on the motor 3 based on the phase currents iu to iw detected by the current sensors 21u to 21w and the magnetic pole position θe detected by the magnetic pole position sensor 22 ( It is configured to (estimate). Specifically, the control unit 30 derives the d-axis current id and the q-axis current iq based on the phase currents iu to iw detected by the current sensors 21u to 21w and the magnetic pole position θe detected by the magnetic pole position sensor 22. Then, by substituting the d-axis current id and the q-axis current iq into the following equation, the torque Tet acting on the motor 3 is derived.

In the above equation, "npole" indicates the number of pole pairs of the motor 3, "φa" indicates the armature interlinkage magnetic flux, "Ld" indicates the d-axis inductance, and "Lq" indicates the q-axis inductance. ..

[Structure of control unit]
As shown in FIG. 1, in this example, the control unit 30 has an abnormality determination unit 31, a switching control unit 32, and an operation control unit 33. That is, the abnormality determination unit 31, the switching control unit 32, and the operation control unit 33 are realized by software and form a part of the functions of the control unit 30.

[Abnormality judgment unit]
The abnormality determination unit 31 is configured to perform abnormality determination on at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20. In this example, the abnormality determination unit 31 determines an abnormality for all of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20. The abnormality determination unit 31 (control unit 30) may determine the abnormality of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 as follows.

<Determination of DC power supply abnormality>
For example, the abnormality determination unit 31 inputs the power supply voltage VP and determines the abnormality of the DC power supply 2 based on the power supply voltage VP. Specifically, the abnormality determination unit 31 determines that the DC power supply 2 has an abnormality when the power supply voltage VP exceeds a predetermined power supply voltage threshold value.

<Abnormality judgment of motor and inverter>
Further, the abnormality determination unit 31 inputs the phase currents iu to iw detected by the current sensors 21u to 21w, and determines the abnormality of the motor 3 and the inverter 11 based on the phase currents iu to iw. Specifically, the abnormality determination unit 31 is a motor when the phase difference between the three phase currents iu to iw deviates from the normal range (for example, the range of 120 ° ± α, α is smaller than 120 °). It is determined that there is an abnormality in 3 and the inverter 11.

<Sensor abnormality judgment>
Further, the abnormality determination unit 31 inputs the output of the sensor 20 (current sensors 21u to 21w and the magnetic pole position sensor 22 in this example), and determines the abnormality of the sensor 20 based on the output of the sensor 20. Specifically, the abnormality determination unit 31 determines the sensor 20 when the length of the period in which the output of the sensor 20 is constant at the maximum level (or the minimum level) is longer than the predetermined normal period length. Judge that there is an abnormality. In general, when an abnormality such as a disconnection occurs in the sensor 20, the output of the sensor 20 becomes constant at the maximum level (or the minimum level).

<Judgment of short-circuit abnormality of switching element>
Further, in this example, whether or not the abnormality determination unit 31 is a short-circuit abnormality in which the switching elements are always on for each of the three high-side switching elements S1 to S3 and the three low-side switching elements S4 to S6. It is configured to determine whether or not. The abnormality determination unit 31 may determine the short-circuit abnormality of the switching elements S1 to S6 as follows.

For example, the abnormality determination unit 31 determines the three phase voltages (U-phase voltage Vu, V-phase voltage Vv, W-phase voltage Vw), the power supply voltage VP, and the ground voltage VG applied to the three output lines LOu to LOw, respectively. Input, and determine the short circuit abnormality of the switching elements S1 to S6 based on these three phase voltages Vu to Vw, the power supply voltage VP, and the ground voltage VG.

Specifically, in the abnormality determination unit 31, the difference between the power supply voltage VP and the U-phase voltage Vu corresponding to the first high-side switching element S1 during the period in which the first high-side switching element S1 should be turned off is an abnormal value. (For example, a value smaller than the normal value corresponding to the difference between the power supply voltage VP and the U-phase voltage Vu when the first high-side switching element S1 is in the off state), the first high-side switching element. The difference between the power supply voltage VP and the U-phase voltage Vu corresponding to the first high-side switching element S1 is a normal value during the period in which S1 is determined to be a short-circuit abnormality and the first high-side switching element S1 should be turned off. In a certain case, it is determined that the first high side switching element S1 is not a short circuit abnormality. The same applies to the second and third high-side switching elements S2 and S3.

Further, in the abnormality determination unit 31, the difference between the U-phase voltage Vu corresponding to the first low-side switching element S4 and the ground voltage VG during the period in which the first low-side switching element S4 should be turned off is an abnormal value (for example, the first). The first low-side switching element S4 has a short-circuit abnormality when the value is smaller than the normal value corresponding to the difference between the U-phase voltage Vu and the ground voltage VG when the low-side switching element S4 is in the off state. When the difference between the U-phase voltage Vu corresponding to the first low-side switching element S4 and the ground voltage VG is a normal value during the period in which the first low-side switching element S4 should be turned off, the first low-side switching is performed. It is determined that the element S4 is not a short circuit abnormality. The same applies to the second and third low-side switching elements S5 and S6.

Further, the abnormality determination unit 31 determines the abnormality of the inverter 11 based on the determination result of the short-circuit abnormality for the six switching elements S1 to S6. Specifically, the abnormality determination unit 31 determines that the inverter 11 has an abnormality when there is a switching element determined to be a short-circuit abnormality among the six switching elements S1 to S6.

<Judgment of opening abnormality of switching element>
Further, in this example, whether or not the abnormality determination unit 31 is an open abnormality in which the switching elements are always off for each of the three high-side switching elements S1 to S3 and the three low-side switching elements S4 to S6. It is configured to determine whether or not. The abnormality determination unit 31 may determine the opening abnormality of the switching elements S1 to S6 as follows.

For example, the abnormality determination unit 31 determines the three phase voltages (U-phase voltage Vu, V-phase voltage Vv, W-phase voltage Vw), the power supply voltage VP, and the ground voltage VG applied to the three output lines LOu to LOw, respectively. The input is input, and the opening abnormality of the switching elements S1 to S6 is determined based on these three phase voltages Vu to Vw, the power supply voltage VP, and the ground voltage VG.

Specifically, in the abnormality determination unit 31, the difference between the power supply voltage VP and the U-phase voltage Vu corresponding to the first high-side switching element S1 during the period in which the first high-side switching element S1 should be turned on is an abnormal value. (For example, a value larger than the normal value corresponding to the difference between the power supply voltage VP and the U-phase voltage Vu when the first high-side switching element S1 is in the ON state), the first high-side switching element. The difference between the power supply voltage VP and the U-phase voltage Vu corresponding to the first high-side switching element S1 is a normal value during the period in which S1 is determined to be an open abnormality and the first high-side switching element S1 should be turned on. In a certain case, it is determined that the first high-side switching element S1 is not an open abnormality. The same applies to the second and third high-side switching elements S2 and S3.

Further, in the abnormality determination unit 31, the difference between the U-phase voltage Vu corresponding to the first low-side switching element S4 and the ground voltage VG during the period in which the first low-side switching element S4 should be turned on is an abnormal value (for example, the first). When the value is larger than the normal value corresponding to the difference between the U-phase voltage Vu and the ground voltage VG when the low-side switching element S4 is in the ON state), the first low-side switching element S4 is open abnormally. When the difference between the U-phase voltage Vu corresponding to the first low-side switching element S4 and the ground voltage VG is a normal value during the period in which the first low-side switching element S4 should be turned off, the first low-side switching is performed. It is determined that the element S4 is not an open abnormality. The same applies to the second and third low-side switching elements S5 and S6.

Further, the abnormality determination unit 31 determines the abnormality of the inverter 11 based on the determination result of the opening abnormality for the six switching elements S1 to S6. Specifically, the abnormality determination unit 31 determines that the inverter 11 has an abnormality when there is a switching element determined to be an open abnormality among the six switching elements S1 to S6.

[Switching control unit]
The switching control unit 32 is configured to perform normal control, three-phase short-circuit control, and fully open control. Further, the switching control unit 32 is configured to perform field weakening control on the motor 3 according to the rotation speed of the motor 3 in normal control. Specifically, in normal control, the switching control unit 32 performs field weakening control on the motor 3 when the rotation speed of the motor 3 exceeds the high rotation threshold, and the rotation speed of the motor 3 sets the high rotation threshold. If it does not exceed the limit, the field weakening control is not performed on the motor 3.

<Configuration example of switching control unit>
FIG. 2 illustrates the configuration of the switching control unit 32. The switching control unit 32 includes a coordinate conversion unit 301, a current command generation unit 302, a current control unit 303, a coordinate inverse conversion unit 304, a PWM signal generation unit 305, and a field weakening control unit 306.

The coordinate conversion unit 301 determines the d-axis current id and the q-axis current iq of the motor 3 based on the phase currents iu to iw detected by the current sensors 21u to 21w and the magnetic pole position θe detected by the magnetic pole position sensor 22. Derived.

The current command generation unit 302 derives the d-axis current command value id * and the q-axis current command value iq * based on the torque command Te. Specifically, the current command generation unit 302 multiplies the torque command Te by the sine value (sinθ) to derive the d-axis current command value id *, and multiplies the torque command Te by the cosine value (cosθ) to q. Derivation of the shaft current command value iq *.

The current control unit 303 uses the d-axis current id and q-axis current iq derived by the coordinate conversion unit 301 and the d-axis current command value id * and q-axis current command value iq * derived by the current command generation unit 302. Based on this, the d-axis voltage command value Vd * and the q-axis voltage command value Vq * are derived. Specifically, the current control unit 303 sets d so that the difference between the d-axis current id and the d-axis current command value id * and the difference between the q-axis current iq and the q-axis current command value iq * are small. The shaft voltage command value Vd * and the q-axis voltage command value Vq * are derived.

The coordinate inverse conversion unit 304 has a U-phase voltage based on the d-axis voltage command value Vd * and the q-axis voltage command value Vq * derived by the current control unit 303 and the magnetic pole position θe detected by the magnetic pole position sensor 22. The command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw * are derived.

The PWM signal generation unit 305 has six switching elements S1 to S6 based on the U-phase voltage command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw * derived by the coordinate inverse conversion unit 304. Generates six gate signals, each supplied to. Specifically, the PWM signal generation unit 305 PWM-controls six gate signals based on the U-phase voltage command value Vu *, the V-phase voltage command value Vv *, and the W-phase voltage command value Vw *.

The field weakening control unit 306 determines whether or not the field weakening control is necessary based on the rotation speed of the motor 3. Specifically, the field weakening control unit 306 determines that it is necessary to perform field weakening control when the rotation speed of the motor 3 exceeds the high rotation threshold, and when the rotation speed of the motor 3 does not exceed the high rotation threshold. It is determined that it is not necessary to implement field weakening control. When the field weakening control is performed, the field weakening control unit 306 controls the operation of the current command generation unit 302 so that the d-axis current command value id * becomes negative. On the other hand, when the field weakening control is not performed, the field weakening control unit 306 releases the control of the current command generation unit 302.

In this example, the switching control unit 32 (specifically, the field weakening control unit 306) is configured to acquire the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. ..

[Operation control unit]
The operation control unit 33 is configured to control the operation of the switching control unit 32 according to the result of the abnormality determination by the abnormality determination unit 31. The operation of the operation control unit 33 is an operation performed until an abnormality is determined by the abnormality determination (normal operation) and an operation performed when the abnormality determination determines that there is an abnormality (abnormality occurrence response operation). ) And the operation (abnormal continuation response operation) performed during the period (abnormal continuation period) after the abnormality is determined by the abnormality determination.

<Normal operation>
The operation control unit 33 is configured to cause the switching control unit 32 to perform normal control until the abnormality determination unit 31 determines that there is an abnormality.

<Operation for responding to abnormal occurrences>
Further, when the operation control unit 33 determines that there is an abnormality by the abnormality determination unit 31, the operation control unit 33 causes the switching control unit 32 to perform either three-phase short-circuit control or full-open control according to the operation state of the motor 3. It is configured as follows. In this example, when the abnormality determination unit 31 determines that there is an abnormality, the operation control unit 33 controls the three-phase short circuit according to at least one of the presence / absence of field weakening control for the motor 3 and the rotation speed of the motor 3. It is configured so that the switching control unit 32 performs either one of the control and the full-open control. Specifically, the operation control unit 33 controls the switching control unit 32 with a three-phase short circuit when the field weakening control for the motor 3 is performed or when the rotation speed of the motor 3 exceeds a predetermined rotation speed threshold. When the field weakening control for the motor 3 is not performed and the rotation speed of the motor 3 does not exceed the rotation speed threshold value, the switching control unit 32 is configured to perform full-open control.

<Operation for continuous abnormalities>
Further, in the period after the abnormality determination unit 31 determines that there is an abnormality (abnormality continuation period), the operation control unit 33 is either a three-phase short-circuit control or a fully open control according to the torque Tet acting on the motor 3. One of them is configured to be performed by the switching control unit 32. Specifically, in the operation control unit 33, when the torque Tet acting on the motor 3 when the three-phase short-circuit control is performed during the abnormal continuation period is lower than the first torque threshold value Tth1, the switching control unit 32 is set to three. The operation of the switching control unit 32 is controlled so as to end the phase short-circuit control and start the full-open control. Further, in the operation control unit 33, when the torque Tet acting on the motor 3 exceeds the second torque threshold value Tth2 when the full-open control is performed during the abnormal continuation period, the switching control unit 32 ends the full-open control. Then, the operation of the switching control unit 32 is controlled so as to start the three-phase short circuit control.

In this example, the motion control unit 33 is configured to acquire the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. Further, the operation control unit 33 acquires (estimates) the torque Tet acting on the motor 3 based on the phase currents iu to iw detected by the current sensors 21u to 21w and the magnetic pole position θe detected by the magnetic pole position sensor 22. It is configured as follows. For example, the operation control unit 33 acquires the torque Tet acting on the motor 3 based on the d-axis current id and the q-axis current iq derived by the coordinate conversion unit 301 (see FIG. 2) of the switching control unit 32.

[Behavior in three-phase short circuit control]
Next, the behavior in the three-phase short-circuit control will be described with reference to FIG. FIG. 3 illustrates the relationship between the torque Tet acting on the motor 3 and the rotation speed of the motor 3 when the three-phase short circuit control is performed. When three-phase short-circuit control is performed, regenerative torque acts on the motor 3. This regenerative torque is a torque having a negative value (that is, a torque acting in the direction opposite to the rotation direction of the motor 3), and as shown in FIG. 3, as the rotation speed of the motor 3 decreases, the motor The absolute value of the torque Tet (regenerative torque having a negative value) acting on 3 tends to gradually increase. Therefore, when the rotation speed of the motor 3 decreases (for example, the vehicle speed of the electric vehicle decreases) when the three-phase short circuit control is performed, the regenerative torque (torque Tet having a negative value) acting on the motor 3 causes. There is a possibility that the rotation speed of the motor 3 will drop sharply.

In the example of FIG. 3, when the rotation speed of the motor 3 is lower than the first rotation speed R1, the absolute value of the torque Tet (regenerative torque having a negative value) acting on the motor 3 increases with respect to the decrease in the rotation speed of the motor 3. (Rate of increase in regenerative torque) is high. In this example, the first torque threshold value Tth1, which is a criterion for switching from the three-phase short-circuit control to the fully open control, acts on the motor 3 when the rotation speed of the motor 3 is the first rotation speed R1 (that is, it acts on the motor 3). The value of the torque acting on the motor 3 is set when the rate of increase in the regenerative torque can be considered to be high).

[Behavior in full open control]
Next, the behavior in the fully open control will be described with reference to FIG. FIG. 4 illustrates the relationship between the torque Tet acting on the motor 3 and the rotation speed of the motor 3 when the fully open control is performed. When the fully open control is performed, the induced voltage of the motor 3 tends to increase as the rotation speed of the motor 3 increases. Therefore, when the rotation speed of the motor 3 increases (for example, the vehicle speed of the electric vehicle increases due to a downhill or the like) when the fully open control is performed, the motor 3 moves to the DC power supply 2 side via the inverter 11. Due to the regenerated power, the power line (power supply line LP and ground line LG) connecting the DC power supply 2 and the inverter 11 may become an overvoltage (for example, a voltage exceeding the legally regulated voltage).

When the induced voltage of the motor 3 increases as the rotation speed of the motor 3 increases and the induced voltage of the motor 3 exceeds the voltage of the DC power supply 2, the torque Tet acting on the motor 3 increases as shown in FIG. growing. In the example of FIG. 4, when the rotation speed of the motor 3 exceeds the second rotation speed R2, the torque Tet acting on the motor 3 becomes large. In this example, the second torque threshold value Tth2, which is the criterion for switching from the fully open control to the three-phase short-circuit control, is when the rotational speed of the motor 3 is the second rotational speed (that is, the induced voltage of the motor 3 is The value of the torque acting on the motor 3 when it can be regarded as exceeding the voltage of the DC power supply 2) is set.

Further, as shown in FIG. 4, when the rotation speed of the motor 3 exceeds the second rotation speed R2, the torque Tet acting on the motor 3 fluctuates greatly. As a result, if the vehicle speed of the electric vehicle increases due to a downhill or the like and the rotation speed of the motor 3 increases while the fully open control is performed, vibration caused by the fluctuation of the torque Tet is generated in the electric vehicle. Therefore, in order to avoid vibration, a second torque threshold value Tth2 that hardly feels vibration to the occupant is set, and if a torque Tet exceeding the second torque threshold value Tth2 is generated, the operation control unit 33 changes from full open control to three-phase. Switch to short circuit control. As a result, the relationship between the torque Tet of the motor 3 and the rotation speed becomes as shown in FIG. 3, and even if the downhill continues and the rotation speed of the motor 3 further increases, the torque Tet hardly fluctuates and vibrates. Can be suppressed.

In FIG. 4, if the operation control unit 33 switches from the fully open control to the three-phase short circuit control based on the rotation speed with the second rotation speed R2 of the motor 3 as the threshold value, the second rotation speed is detected due to the second rotation speed. Switching may be performed after the torque threshold value Tth2 is exceeded. Therefore, in order to suppress the vibration of the electric vehicle so that the occupant hardly feels it, either full-open control or three-phase short-circuit control may be performed according to the torque Tet acting on the motor 3. ..

[Switching operation of field weakening control]
Next, with reference to FIG. 5, the switching operation of the field weakening control in the normal control of the switching control unit 32 will be described. This switching operation is repeated until the abnormality determination unit 31 determines that there is an abnormality.

<Step S11>
First, the switching control unit 32 (specifically, the field weakening control unit 306) acquires the rotation speed of the motor 3. In this example, the switching control unit 32 calculates the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. Then, the switching control unit 32 determines whether or not the rotation speed of the motor 3 exceeds the high rotation threshold value. If the rotation speed of the motor 3 exceeds the high rotation threshold value, the process proceeds to step S12, and if not, the process proceeds to step S13.

<Step S12>
When the rotation speed of the motor 3 exceeds the high rotation threshold value, the switching control unit 32 performs field weakening control with respect to the motor 3. For example, the switching control unit 32 makes the d-axis current of the motor 3 negative based on the phase currents iu to iw detected by the current sensors 21u to 21w and the magnetic pole position θe detected by the magnetic pole position sensor 22. In addition, the switching operation of the inverter 11 is controlled by PWM controlling the six gate signals supplied to the six switching elements S1 to S6, respectively. By passing a negative d-axis current in this way, the magnetic flux in the d-axis direction can be reduced by utilizing the demagnetization effect due to the armature reaction. As a result, the counter electromotive force generated by the rotation of the motor 3 can be reduced, so that the rotation speed of the motor 3 can be increased.

<Step S13>
On the other hand, when the rotation speed of the motor 3 does not exceed the high rotation threshold value, the switching control unit 32 releases the field weakening control for the motor 3. For example, the switching control unit 32 PWM-controls six gate signals supplied to each of the six switching elements S1 to S6 so that other synchronous control such as maximum torque current control is performed on the motor 3. Controls the switching operation of the inverter 11.

[Operation for responding to abnormal occurrence]
Next, with reference to FIG. 6, the operation for dealing with the occurrence of an abnormality in the operation control unit 33 will be described. This abnormality occurrence response operation is performed when it is determined by the abnormality determination unit 31 that there is an abnormality.

<Step S21>
First, the operation control unit 33 determines whether or not the field weakening control for the motor 3 is performed. For example, the switching control unit 32 (specifically, the field weakening control unit 306) is a flag indicating that the field weakening control is being performed when the field weakening control for the motor 3 is being performed (hereinafter, “field weakening flag””. When the field weakening control for the motor 3 is released, the field weakening flag is lowered. Then, the operation control unit 33 determines whether or not the field weakening control is performed on the motor 3 based on the field weakening flag. If the field weakening control for the motor 3 is not performed (for example, when the field weakening flag is lowered), the process proceeds to step S23, and if not, the process proceeds to step S22.

<Step S22>
Next, the operation control unit 33 acquires the rotation speed of the motor 3. In this example, the motion control unit 33 calculates the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. Then, the operation control unit 33 determines whether or not the rotation speed of the motor 3 exceeds the rotation speed threshold value. If the rotation speed of the motor 3 does not exceed the rotation speed threshold value, the process proceeds to step S23, and if not, the process proceeds to step S24. The rotation speed threshold may be, for example, a rotation speed at which the rate of increase in the absolute value of the torque Tet acting on the motor 3 does not increase, that is, the first rotation speed R1, based on FIG.

<Step S23>
When the field weakening control for the motor 3 is not performed, or when the field weakening control for the motor 3 is performed and the rotation speed of the motor 3 does not exceed the rotation speed threshold value, the operation control unit 33 performs the three-phase short-circuit control. The switching control unit 32 is controlled so that the fully open control is performed among the fully open controls. As a result, all three high-side switching elements S1 to S3 and three low-side switching elements S4 to S6 are turned off, and the switching operation of the inverter 11 is stopped.

<Step S24>
On the other hand, when the field weakening control for the motor 3 is performed and the rotation speed of the motor 3 exceeds the rotation speed threshold value, the operation control unit 33 performs the three-phase short-circuit control out of the three-phase short-circuit control and the fully open control. Controls the switching control unit 32. As a result, one of the high-side switching element group consisting of the three high-side switching elements S1 to S3 and the low-side switching element group consisting of the three low-side switching elements S4 to S6 is turned on and the other is switched. The element group is turned off, and the switching operation of the inverter 11 is stopped.

[Characteristics of three-phase short-circuit control and full-open control]
When the abnormality determination unit 31 determines that there is an abnormality (for example, when an abnormality occurs in which the DC power supply 2 fails while the electric vehicle is running), when the full-open control is performed, the stator coil of the motor 3 is subjected to. The stored electric power is supplied to the smoothing capacitor 12 via a freewheeling diode connected in antiparallel to the switching elements S1 to S6 to charge the smoothing capacitor 12, and as a result, the voltage between terminals of the smoothing capacitor 12 rises. become. The increase in the voltage between the terminals of the smoothing capacitor 12 tends to increase as the rotation speed of the motor 3 increases. That is, when it is determined by the abnormality determination unit 31 that there is an abnormality and full-open control is performed, the higher the rotation speed of the motor 3, the more the power line connecting the DC power supply 2 and the inverter 11 (power supply line LP and grounding). The voltage applied to the line LG) becomes high, and there is a high possibility that the power line connecting the DC power supply 2 and the inverter 11 becomes an overvoltage.

On the other hand, when the abnormality determination unit 31 determines that there is an abnormality (for example, when an abnormality occurs in which the DC power supply 2 fails while the electric vehicle is running), three-phase short-circuit control is performed, and three outputs are output. The lines LOu to LOw are connected to each other via small resistors (on-resistance of switching elements S1 to S6), and as a result, three phase currents iu to iw flowing through the three output lines LOu to LOw are instantaneously generated. Will increase. The instantaneous increase in the phase currents iu to iwa tends to increase as the rotation speed of the motor 3 decreases.

Therefore, when the three-phase short-circuit control is performed when the rotation speed of the motor 3 is relatively high when the abnormality determination unit 31 determines that there is an abnormality, the abnormality determination unit 31 determines that there is an abnormality. By performing full-open control when the rotation speed of the motor 3 of the motor 3 is relatively low, the overvoltage and phase currents of the power lines (power supply line LP and ground line LG) connecting the DC power supply 2 and the inverter 11 are iu to iw. Both instantaneous increases can be effectively suppressed.

[Operation for continuous abnormalities]
Next, with reference to FIG. 7, the operation for dealing with abnormal continuation of the operation control unit 33 will be described. This abnormality continuation response operation is repeatedly performed during the period (abnormality continuation period) after the abnormality determination unit 31 determines that there is an abnormality.

<Step S25>
First, the operation control unit 33 determines whether or not the three-phase short-circuit control is performed in the switching control unit 32. If the switching control unit 32 is performing three-phase short-circuit control, the process proceeds to step S26, and if not, the process proceeds to step S28.

<Step S26>
When the three-phase short circuit control is performed, the operation control unit 33 determines whether or not the torque Tet acting on the motor 3 is lower than the first torque threshold value Tth1. If the torque Tet acting on the motor 3 is lower than the first torque threshold value Tth1, the process proceeds to step S27.

<Step S27>
When the torque Tet acting on the motor 3 falls below the first torque threshold value Tth1 when the three-phase short-circuit control is performed, the operation control unit 33 ends the three-phase short-circuit control by the switching control unit 32 to perform full-open control. The switching control unit 32 is controlled so as to start.

<Step S28>
On the other hand, when the three-phase short-circuit control is not performed in the switching control unit 32 (that is, when the full-open control is performed in the switching control unit 32), the operation control unit 33 has a torque Tet acting on the motor 3. 2 It is determined whether or not the torque threshold value Tth2 is exceeded. If the torque Tet acting on the motor 3 exceeds the second torque threshold value Tth2, the process proceeds to step S29.

<Step S29>
When the torque Tet acting on the motor 3 exceeds the second torque threshold value Tth2 when the fully open control is performed, the operation control unit 33 ends the full open control of the switching control unit 32 and performs the three-phase short circuit control. The switching control unit 32 is controlled so as to start.

[Effect of Embodiment 1]
As described above, by performing either the three-phase short-circuit control or the fully open control according to the torque Tet acting on the motor 3 during the abnormality continuation period after the abnormality is determined by the abnormality determination, the motor 3 Both the sudden deceleration of the power supply 2 and the overvoltage of the power line connecting the DC power supply 2 and the inverter 11 can be effectively suppressed.

Further, by acquiring (estimating) the torque Tet acting on the motor 3 based on the phase currents iu to iw detected by the current sensors 21u to 21w and the magnetic pole position θe detected by the magnetic pole position sensor 22, the motor 3 It is not necessary to separately provide a torque sensor (not shown) that detects the torque acting on the motor.

Further, when it is determined by the abnormality determination that there is an abnormality, the three-phase phase is determined according to the operating state of the motor 3 (specifically, whether or not the field weakening control is performed on the motor 3 and at least one of the rotation speeds of the motor 3). By performing either short-circuit control or full-open control, it is possible to appropriately perform control according to the operating state of the motor 3 among the three-phase short-circuit control and full-open control.

Further, the rotation speed sensor (not shown) that detects the rotation speed of the motor 3 by acquiring (calculating) the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22 is omitted. Can be done.

Further, by performing abnormality determination on all of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20, not only when an abnormality occurs in the DC power supply 2, but also the DC power supply 2, the motor 3, and the inverter 11 When an abnormality occurs in at least one of the sensors 20, three-phase short-circuit control and full-open control can be selectively performed according to the operating state of the motor 3. As a result, it is possible to suppress not only the overvoltage of the power line (power supply line LP and the ground line LG) due to the abnormality of the DC power supply 2, but also the overvoltage of the power line due to the abnormality of the DC power supply 2, the motor 3, the inverter 11 and the sensor 20.

(Variation example of Embodiment 1)
Note that step S22 may be omitted in the operation for responding to the occurrence of an abnormality in the operation control unit 33 shown in FIG. That is, when the abnormality determination unit 31 determines that there is an abnormality, the operation control unit 33 switches between the three-phase short-circuit control and the fully open control depending on whether or not the field weakening control is performed on the motor 3. It may be configured to be performed by the control unit 32. Specifically, the operation control unit 33 causes the switching control unit 32 to perform three-phase short-circuit control when the field weakening control for the motor 3 is performed, and when the field weakening control for the motor 3 is not performed, the operation control unit 33 causes the switching control unit 32 to perform the field weakening control. It may be configured so that the switching control unit 32 performs full-open control.

Further, step S21 may be omitted in the operation for responding to the occurrence of an abnormality in the operation control unit 33 shown in FIG. That is, when the abnormality determination unit 31 determines that there is an abnormality, the operation control unit 33 sets either the three-phase short-circuit control or the fully open control to the switching control unit 32 according to the rotation speed of the motor 3. It may be configured to do so. Specifically, the operation control unit 33 causes the switching control unit 32 to perform three-phase short circuit control when the rotation speed of the motor 3 exceeds a predetermined rotation speed threshold value, and the rotation speed of the motor 3 becomes the rotation speed. When the threshold value is not exceeded, the switching control unit 32 may be configured to perform full-open control.

(Embodiment 2)
FIG. 8 illustrates the configuration of the motor control device 10 according to the second embodiment. The motor control device 10 according to the second embodiment has a different configuration of the control unit 30 than the motor control device 10 according to the first embodiment. Other configurations of the motor control device 10 according to the second embodiment are the same as the configurations of the motor control device 10 according to the first embodiment.

As shown in FIG. 8, in the second embodiment, the abnormality determination unit 31 is configured by hardware separate from the switching control unit 32 and the operation control unit 33. Then, the abnormality determination unit 31 performs abnormality determination on at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20, and if it is determined that there is an abnormality in the abnormality determination, the abnormality detection signal S31 is used as an operation control unit. Output to 33. The operation control unit 33 causes the switching control unit 32 to perform normal control until the abnormality detection signal S31 is output by the abnormality determination unit 31. Further, when the abnormality detection signal S31 is output by the abnormality determination unit 31, the operation control unit 33 performs either three-phase short-circuit control or full-open control to the switching control unit 32 according to the operation state of the motor 3. Let me. Then, in the operation control unit 33, the operation control unit 33 has a three-phase short circuit according to the torque Tet acting on the motor 3 in the period (abnormality continuation period) after the abnormality detection signal S31 is output by the abnormality determination unit 31. The switching control unit 32 is made to perform either control or full-open control.

The normal operation of the operation control unit 33 in the second embodiment (operation performed until the abnormality detection signal S31 is output), the abnormality occurrence response operation (operation performed when the abnormality detection signal S31 is output), and the abnormality continuation. The corresponding operation (the operation performed during the period after the abnormality detection signal S31 is output) is the same as the normal operation, the abnormality occurrence response operation, and the abnormality continuation response operation of the operation control unit 33 in the first embodiment.

Further, as shown in FIG. 8, in the second embodiment, the operation control unit 33 is configured by hardware separate from the switching control unit 32, and is one of normal control, three-phase short-circuit control, and full-open control. The control signal S33 for performing the above operation is output to the switching control unit 32. The switching control unit 32 performs one of normal control, three-phase short-circuit control, and full-open control in response to the control signal S33 output by the operation control unit 33.

In the second embodiment, the switching control unit 32 includes, for example, an arithmetic processing unit such as a CPU, a storage unit such as a memory for storing programs and information for operating the arithmetic processing unit, and switching elements S1 to S6. It is composed of a drive circuit such as a gate drive IC that supplies a gate signal to the switch element S1 to S6 to control the on / off of the switching elements S1 to S6. The operation of the switching control unit 32 in the second embodiment is the same as the operation of the switching control unit 32 in the first embodiment.

[Effect of Embodiment 2]
As described above, by configuring the abnormality determination unit 31 by hardware, the abnormality determination in the abnormality determination unit 31 can be performed more quickly than in the case where the abnormality determination unit 31 is configured by software.

Further, by configuring the motion control unit 33 by hardware, it is possible to control the switching control unit 32 by the motion control unit 33 more quickly than when the motion control unit 33 is configured by software.

In the second embodiment, the abnormality determination unit 31 and the operation control unit 33 may be integrally formed. That is, the abnormality determination unit 31 and the operation control unit 33 may be configured by one piece of hardware.

In the description of the first and second embodiments, the case where the control unit 30 (switching control unit 32 and operation control unit 33) acquires the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22 is used. As an example, the motor control device 10 may be provided with a rotation speed sensor (not shown) that detects the rotation speed of the motor 3. The control unit 30 (switching control unit 32 and operation control unit 33) may be configured to acquire the rotation speed of the motor 3 by inputting the rotation speed detected by the rotation speed sensor.

Further, in the description of the first and second embodiments, the control unit 30 (operation control unit 33) is based on the phase currents iu to iw detected by the current sensors 21u to 21w and the magnetic pole position θe detected by the magnetic pole position sensor 22. Although the case of acquiring the torque Tet acting on the motor 3 is taken as an example, a torque sensor (not shown) for detecting the torque acting on the motor 3 may be provided in the motor control device 10. Then, the control unit 30 (operation control unit 33) may be configured to acquire the torque Tet acting on the motor 3 by inputting the torque detected by the torque sensor.

Further, the first and second embodiments and the modified examples may be combined as appropriate. The above embodiments and modifications are essentially preferred examples and are not intended to limit the scope of the invention, its applications, or its uses.

(Embodiment 3)
FIG. 9 illustrates the configuration of the motor control device 40 according to the third embodiment. The motor control device 40 according to the third embodiment is configured by replacing the control unit 30 of the motor control device 10 according to the first embodiment with a control unit 50. Other configurations of the motor control device 40 according to the third embodiment are the same as the configurations of the motor control device 10 according to the first embodiment.

[Control unit]
The control unit 50 is configured to control the switching operation of the inverter 11 based on the information detected by the sensor 20, a control command input from the outside, and the like. For example, the control unit 50 supplies a gate signal to the arithmetic processing unit such as a CPU, a storage unit such as a memory for storing programs and information for operating the arithmetic processing unit, and switching elements S1 to S6 for switching. It is composed of a drive circuit such as a gate drive IC that controls on / off of the elements S1 to S6.

In this example, the control unit 50 includes the phase currents iu to iw detected by the current sensors 21u to 21w, the magnetic pole position θe of the motor 3 detected by the magnetic pole position sensor 22, the power supply voltage VP, and the motor 3. A torque command Te indicating a target torque (for example, a torque corresponding to the operation amount of the accelerator pedal of an electric vehicle) is input.

Further, in this example, the control unit 50 has an abnormality determination unit 51, a normal control unit 52, and an abnormality control unit 53. That is, the abnormality determination unit 51, the normal control unit 52, and the abnormality control unit 53 are realized by software and form a part of the functions of the control unit 50.

[Abnormality judgment unit]
The abnormality determination unit 51 is configured to perform abnormality determination on at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20. In this example, the abnormality determination unit 51 determines an abnormality for all of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20. The abnormality determination unit 51 may determine the abnormality of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 in the same manner as the abnormality determination unit 31 of the motor control device 10 according to the first embodiment.

[Normal control unit]
The normal control unit 52 of the inverter 11 is based on the information detected by the sensor 20 until at least one of the DC power supply 2, the motor 3, the inverter 11 and the sensor 20 is determined to be abnormal by the abnormality determination unit 51. Control switching operation. Specifically, the normal control unit 52 detects signals (specifically) from various sensors such as the current sensors 21u to 21w and the magnetic pole position sensor 22 so that the torque of the motor 3 becomes the target torque indicated by the torque command Te. The switching operation of the inverter 11 is controlled based on the phase currents iu to iw flowing through the three output lines LOu to LOw and the magnetic pole position θe of the motor 3 respectively.

In this example, the normal control unit 52 performs the field weakening control with respect to the motor 3 according to the rotation speed of the motor 3 in the same manner as the field weakening control operation by the control unit 30 of the first embodiment described with reference to FIG. It is configured in.

[Abnormality control unit]
When the abnormality control unit 53 determines that at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 is abnormal by the abnormality determination unit 51, the abnormality control unit 53 performs three-phase short-circuit control according to the operating state of the motor 3. Select either one of the full open control. In the three-phase short-circuit control, the abnormality control unit 53 is a switching element group of one of a high-side switching element group consisting of three high-side switching elements S1 to S3 and a low-side switching element group consisting of three low-side switching elements S4 to S6. Is turned on and the other switching element group is turned off. In the fully open control, the abnormality control unit 53 turns off all of the high-side switching element group composed of the three high-side switching elements S1 to S3 and the low-side switching element group composed of the three low-side switching elements S4 to S6.

In this example, the abnormality control unit 53 determines whether or not the normal control unit 52 implements field weakening control for the motor 3 and the motor 3 in the same manner as the abnormality occurrence response operation by the control unit 30 of the first embodiment described with reference to FIG. It is configured to select and perform either three-phase short-circuit control or full-open control according to at least one of the rotation speeds.

The features of the three-phase short-circuit control and the fully open control are as described in the first embodiment. Three-phase short-circuit control is performed when the rotation speed of the motor 3 is relatively high when the abnormality determination unit 51 determines that there is an abnormality, while the motor when the abnormality determination unit 51 determines that there is an abnormality. By performing full-open control when the rotation speed of 3 is relatively low, it is possible to effectively suppress both an increase in the voltage between terminals of the smoothing capacitor 12 and an instantaneous increase in the phase currents iu to iw. ..

[Details of three-phase short circuit control]
Next, the details of the three-phase short-circuit control by the abnormality control unit 53 will be described with reference to FIG. 10.

<Step S31>
First, the abnormality control unit 53 determines an abnormality in the six switching elements (three high-side switching elements S1 to S3 and three low-side switching elements S4 to S6) based on the result of the abnormality determination by the abnormality determination unit 51. It is determined whether or not there is a switching element determined by the unit 31 to be a short circuit abnormality. If there is a switching element determined to have a short-circuit abnormality among the six switching elements S1 to S6, the process proceeds to step S32, and if not, the process proceeds to step S33.

<Step S32>
When there is a switching element determined to be a short-circuit abnormality among the six switching elements S1 to S6, the abnormality control unit 53 includes a high-side switching element group composed of three high-side switching elements S1 to S3 and three low-sides. Among the low-side switching element groups including the switching elements S4 to S6, the switching element group including the switching element determined to be a short-circuit abnormality by the abnormality determination unit 51 is turned on. For example, when the abnormality determination unit 51 determines that the first high-side switching element S1 has a short-circuit abnormality, the abnormality control unit 53 turns on the three high-side switching elements S1 to S3 and three low-side switching elements. The gate signals supplied to the six switching elements S1 to S6 are controlled so that the elements S4 to S6 are turned off.

<Step S33>
On the other hand, when there is no switching element determined to be a short-circuit abnormality among the six switching elements S1 to S6, the abnormality control unit 53 determines the abnormality based on the result of the abnormality determination by the abnormality determination unit 51, and the six switching elements ( It is determined whether or not there is a switching element determined to be an open abnormality by the abnormality determination unit 51 among the three high-side switching elements S1 to S3 and the three low-side switching elements S4 to S6). If there is a switching element determined to be open abnormality among the six switching elements S1 to S6, the process proceeds to step S34, and if not, the process proceeds to step S35.

<Step S34>
When there is a switching element determined to be an open abnormality among the six switching elements S1 to S6, the abnormality control unit 53 includes a high-side switching element group composed of three high-side switching elements S1 to S3 and three low-sides. Among the low-side switching element groups including the switching elements S4 to S6, the switching element group including the switching element determined to be an open abnormality by the abnormality determination unit 51 is turned off. For example, when the abnormality determination unit 51 determines that the first high-side switching element S1 is open, the abnormality control unit 53 turns off the three high-side switching elements S1 to S3 and three low-side switching elements. The gate signals supplied to the six switching elements S1 to S6 are controlled so that the elements S4 to S6 are turned on.

<Step S35>
When there is no switching element determined to be a short-circuit abnormality and there is no switching element determined to be an opening abnormality among the six switching elements S1 to S6, the abnormality control unit 53 uses the three high-side switching elements S1. Of the high-side switching element group consisting of ~ S3 and the low-side switching element group consisting of three low-side switching elements S4 to S6, a predetermined switching element group is turned on. For example, if none of the six switching elements S1 to S6 is determined to have a short circuit abnormality and there is no switching element determined to be an open abnormality, switching to be turned on in the three-phase short circuit control. When the low-side switching element group is predetermined as the element group, the abnormality control unit 53 turns off the three high-side switching elements S1 to S3 and turns on the three low-side switching elements S4 to S6. In addition, the gate signals supplied to the six switching elements S1 to S6 are controlled.

[Effect of Embodiment 3]
As described above, by performing abnormality determination not only on the DC power supply 2 but also on the DC power supply 2, the motor 3, the inverter 11, and the sensor 20, not only when an abnormality occurs in the DC power supply 2, but also the DC power supply When an abnormality occurs in at least one of 2, the motor 3, the inverter 11, and the sensor 20, three-phase short-circuit control and full-open control can be selectively performed according to the operating state of the motor 3. As a result, it is possible to suppress not only the overvoltage of the power line (power supply line LP and the ground line LG) due to the abnormality of the DC power supply 2, but also the overvoltage of the power line due to the abnormality of the DC power supply 2, the motor 3, the inverter 11 and the sensor 20.

Further, in the three-phase short-circuit control, the short-circuit abnormality is determined by the abnormality determination unit 51 among the high-side switching element group consisting of three high-side switching elements S1 to S3 and the low-side switching element group consisting of three low-side switching elements S4 to S6. By turning on the switching element group including the determined switching element, a short-circuit abnormality has occurred in the six switching elements (three high-side switching elements S1 to S3 and three low-side switching elements S4 to S6). Even in this case, the three-phase short circuit control can be performed normally.

Further, in the three-phase short circuit control, the abnormality determination unit 51 among the high-side switching element group consisting of three high-side switching elements S1 to S3 and the low-side switching element group consisting of three low-side switching elements S4 to S6 determines that the opening is abnormal. By turning off the switching element group including the determined switching element, an opening abnormality has occurred in the six switching elements (three high-side switching elements S1 to S3 and three low-side switching elements S4 to S6). Even in this case, the three-phase short circuit control can be performed normally.

Further, by selecting either three-phase short-circuit control or full-open control according to at least one of the presence / absence of field weakening control for the motor 3 by the normal control unit 52 and the rotation speed of the motor 3, the DC power supply 2 When an abnormality occurs in at least one of the motor 3, the inverter 11, and the sensor 20, the three-phase short-circuit control and the fully open control can be appropriately controlled according to the operating state of the motor 3.

Further, the rotation speed sensor (not shown) that detects the rotation speed of the motor 3 by acquiring (calculating) the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22 is omitted. Can be done.

(Modified Example of Embodiment 3)
Note that step S22 may be omitted in the operation by the abnormality control unit 53 shown in FIG. That is, the abnormality control unit 53 may be configured to select either three-phase short-circuit control or full-open control depending on whether or not the field weakening control for the motor 3 is performed by the normal control unit 52. Specifically, the abnormality control unit 53 selects the three-phase short-circuit control when the field weakening control for the motor 3 is performed by the normal control unit 52, and the field weakening control for the motor 3 is performed by the normal control unit 52. It may be configured to select full open control when it is not present.

Further, step S21 may be omitted in the operation by the abnormality control unit 53 shown in FIG. That is, the abnormality control unit 53 may be configured to select either three-phase short-circuit control or full-open control according to the rotation speed of the motor 3. Specifically, the abnormality control unit 53 selects the three-phase short circuit control when the rotation speed of the motor 3 exceeds a predetermined rotation speed threshold, and when the rotation speed of the motor 3 does not exceed the rotation speed threshold. It may be configured to select full open control.

(Embodiment 4)
FIG. 11 illustrates the configuration of the motor control device 40 according to the fourth embodiment. The motor control device 40 according to the fourth embodiment has a different configuration of the control unit 50 than the motor control device 40 according to the third embodiment. Other configurations of the motor control device 40 according to the fourth embodiment are the same as the configurations of the motor control device 40 according to the third embodiment.

As shown in FIG. 11, the control unit 50 of the fourth embodiment has a different configuration of the abnormality control unit 53 than the control unit 50 of the third embodiment. Other configurations of the control unit 50 of the fourth embodiment are the same as the configuration of the control unit 50 of the third embodiment.

[Abnormality control unit]
The abnormality control unit 53 of the fourth embodiment has an abnormality control selection unit 531 and an abnormality control execution unit 532.

<Abnormality control selection unit>
The abnormality control selection unit 531 has a three-phase short circuit according to the operating state of the motor 3 before the abnormality determination unit 51 determines that at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 is abnormal. Select either control or full open control.

In this example, the abnormality control selection unit 531 either performs three-phase short-circuit control or full-open control according to at least one of the presence / absence of field weakening control for the motor 3 by the normal control unit 52 and the rotation speed of the motor 3. Is configured to select. Specifically, the abnormality control selection unit 531 performs a three-phase short circuit when the field weakening control for the motor 3 is performed by the normal control unit 52 or when the rotation speed of the motor 3 exceeds a predetermined rotation speed threshold. Control is selected, and when the field weakening control for the motor 3 is not performed by the normal control unit 52 and the rotation speed of the motor 3 does not exceed the rotation speed threshold, the fully open control is selected.

In this example, the abnormality control selection unit 531 is configured to acquire the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22, similarly to the normal control unit 52. Specifically, the abnormality control selection unit 531 calculates the rotation speed of the motor 3 by differentiating the magnetic pole position θe detected by the magnetic pole position sensor 22.

<Abnormality control execution unit>
When the abnormality control execution unit 532 determines that at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 is abnormal by the abnormality determination unit 51, the abnormality control is controlled out of the three-phase short circuit control and the fully open control. The control selected by the selection unit 531 is performed.

Further, in this example, the abnormality control execution unit 532 has a high-side switching element group composed of three high-side switching elements S1 to S3 and a low-side switching element group composed of three low-side switching elements S4 to S6 in the three-phase short-circuit control. Of these, the switching element group including the switching element determined to be a short-circuit abnormality by the abnormality determination unit 51 is configured to be turned on.

Further, in this example, the abnormality control execution unit 532 has a high-side switching element group composed of three high-side switching elements S1 to S3 and a low-side switching element group composed of three low-side switching elements S4 to S6 in the three-phase short-circuit control. Of these, the switching element group including the switching element determined to be an open abnormality by the abnormality determination unit 51 is configured to be turned off.

[Operation by abnormality control selection unit]
Next, the operation by the abnormality control selection unit 531 will be described with reference to FIG. The operation by the abnormality control selection unit 531 is repeated until the abnormality determination unit 51 determines that at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 is abnormal.

<Step S41>
First, similarly to step S21 shown in FIG. 6, the abnormality control selection unit 531 determines whether or not the field weakening control for the motor 3 is performed by the normal control unit 52. If the field weakening control for the motor 3 is not performed, the process proceeds to step S43, and if not, the process proceeds to step S42.

<Step S42>
Next, similarly to step S22 shown in FIG. 6, the abnormality control selection unit 531 acquires the rotation speed of the motor 3 and determines whether or not the rotation speed of the motor 3 exceeds the rotation speed threshold value. If the rotation speed of the motor 3 does not exceed the rotation speed threshold value, the process proceeds to step S43, and if not, the process proceeds to step S44. The rotation speed threshold value may be the first rotation speed R1 as in FIG.

<Step S43>
When the field weakening control for the motor 3 is not performed by the normal control unit 52, or when the field weakening control for the motor 3 is performed and the rotation speed of the motor 3 does not exceed the rotation speed threshold value, the abnormality control selection unit 531 , Select full-open control from three-phase short-circuit control and full-open control. For example, the abnormality control selection unit 531 lowers a flag (hereinafter referred to as “processing flag”) for identifying which control is selected, the three-phase short-circuit control or the fully open control. That is, when the processing flag is set, the three-phase short-circuit control or the full-open control is selected, and when the processing flag is set, the three-phase short-circuit control is selected. And the full-open control is selected from the full-open control.

<Step S44>
On the other hand, when the field weakening control for the motor 3 is performed by the normal control unit 52 and the rotation speed of the motor 3 exceeds the rotation speed threshold value, the abnormality control selection unit 531 has three phases of three-phase short-circuit control and full-open control. Select short circuit control. For example, the abnormality control selection unit 531 sets the processing flag.

[Operation by the error control execution unit]
Next, the operation by the abnormality control execution unit 532 will be described with reference to FIG. The operation by the abnormality control execution unit 532 is performed when the abnormality determination unit 51 determines that at least one of the DC power supply 2, the motor 3, the inverter 11 and the sensor 20 is abnormal.

<Step S51>
First, the abnormality control execution unit 532 determines whether or not the three-phase short-circuit control is selected from the three-phase short-circuit control and the fully open control (for example, whether or not the processing flag is set) by the abnormality control selection unit 531. .. If the three-phase short-circuit control is selected by the abnormality control selection unit 531 (when the processing flag is set), the process proceeds to step S52, and if not, the process proceeds to step S53.

<Step S52>
When the three-phase short-circuit control is selected by the abnormality control selection unit 531, the abnormality control execution unit 532 performs the three-phase short-circuit control out of the three-phase short-circuit control and the fully open control. As a result, one of the high-side switching element group consisting of the three high-side switching elements S1 to S3 and the low-side switching element group consisting of the three low-side switching elements S4 to S6 is turned on and the other is switched. The element group is turned off, and the switching operation of the inverter 11 is stopped. The details of the three-phase short-circuit control by the abnormality control execution unit 532 may be the same as the details of the three-phase short-circuit control by the abnormality control unit 53 shown in FIG.

<Step S53>
On the other hand, when the three-phase short-circuit control is not selected by the abnormality control selection unit 531 (that is, when the full-open control is selected), the abnormality control execution unit 532 is fully open out of the three-phase short-circuit control and the full-open control. Take control. As a result, all three high-side switching elements S1 to S3 and three low-side switching elements S4 to S6 are turned off, and the switching operation of the inverter 11 is stopped.

[Effect of Embodiment 4]
As described above, one of the three-phase short-circuit control and the fully open control can be selected according to the operating state of the motor 3 before the abnormality determination unit 51 determines that there is an abnormality. When it is determined by the determination unit 51 that there is an abnormality, three-phase short-circuit control or full-open control can be quickly performed.

(Modified Example of Embodiment 4)
Further, step S42 may be omitted in the operation by the abnormality control selection unit 531 shown in FIG. That is, the abnormality control selection unit 531 may be configured to select either three-phase short-circuit control or full-open control depending on whether or not the field weakening control for the motor 3 is performed by the normal control unit 52. .. Specifically, the abnormality control selection unit 531 selects three-phase short-circuit control when the normal control unit 52 performs weakening field control for the motor 3, and the normal control unit 52 performs weakening field control for the motor 3. It may be configured to select full open control when it is not.

Further, step S41 may be omitted in the operation by the abnormality control selection unit 531 shown in FIG. That is, the abnormality control selection unit 531 may be configured to select either three-phase short-circuit control or full-open control according to the rotation speed of the motor 3. Specifically, the abnormality control selection unit 531 selects three-phase short-circuit control when the rotation speed of the motor 3 exceeds a predetermined rotation speed threshold, and when the rotation speed of the motor 3 does not exceed the rotation speed threshold. May be configured to select full open control.

(Embodiment 5)
FIG. 14 illustrates the configuration of the motor control device 40 according to the fifth embodiment. The motor control device 40 according to the fifth embodiment has a different configuration of the control unit 50 than the motor control device 40 according to the third embodiment. Other configurations of the motor control device 40 according to the fifth embodiment are the same as the configurations of the motor control device 40 according to the third embodiment.

As shown in FIG. 14, in the fifth embodiment, the abnormality determination unit 51 is composed of hardware separate from the normal control unit 52 and the abnormality control unit 53. In this example, the normal control unit 52 and the abnormality control unit 53 are included in the control processing unit 55. The control processing unit 55 supplies a gate signal to, for example, an arithmetic processing unit such as a CPU, a storage unit such as a memory for storing programs and information for operating the arithmetic processing unit, and switching elements S1 to S6. It is composed of a drive circuit such as a gate drive IC that controls on / off of the switching elements S1 to S6. That is, in this example, the normal control unit 52 and the abnormality control unit 53 are realized by software and form a part of the functions of the control processing unit 55.

In the fifth embodiment, the abnormality determination unit 51 is configured to output an abnormality detection signal S51 when it is determined that at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 is abnormal.

Further, in the fifth embodiment, the normal control unit 52 is configured to control the switching operation of the inverter 11 based on the information detected by the sensor 20 until the abnormality detection signal S51 is output by the abnormality determination unit 51. ing. The operation by the normal control unit 52 of the fifth embodiment (the operation performed until the abnormality detection signal S51 is output by the abnormality determination unit 51) is the operation by the normal control unit 52 of the third embodiment (the abnormality is caused by the abnormality determination unit 51). It is the same as the operation performed until it is determined.

Then, in the fifth embodiment, when the abnormality detection signal S51 is output by the abnormality determination unit 51, the abnormality control unit 53 selects either three-phase short-circuit control or full-open control according to the operating state of the motor. It is configured to do so. The operation by the abnormality control unit 53 of the fifth embodiment (the operation performed after the abnormality detection signal S51 is output by the abnormality determination unit 51) is the operation by the abnormality control unit 53 of the first embodiment (the abnormality is caused by the abnormality determination unit 51). It is the same as the operation performed after it is determined.

The other configurations of the control unit 50 of the fifth embodiment are the same as the configurations of the control unit 50 of the third embodiment.

[Effect of Embodiment 5]
As described above, by configuring the abnormality determination unit 51 by hardware, the abnormality determination in the abnormality determination unit 51 can be performed more quickly than in the case where the abnormality determination unit 51 is configured by software.

The configuration of the fifth embodiment may be applied to the fourth embodiment. That is, in the fourth embodiment, the abnormality determination unit 51 is composed of hardware separate from the normal control unit 52 and the abnormality control unit 53, and at least one of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 is abnormal. If it is determined that the above is true, the abnormality detection signal S51 may be output.

The normal control unit 52 may be configured to control the switching operation of the inverter 11 based on the information detected by the sensor 20 until the abnormality detection signal S51 is output by the abnormality determination unit 51. Then, when the abnormality detection signal S51 is output by the abnormality determination unit 51, the abnormality control unit 53 is configured to select either three-phase short-circuit control or full-open control according to the operating state of the motor. It may have been done.

Specifically, the abnormality control selection unit 531 selects either three-phase short-circuit control or full-open control according to the operating state of the motor 3 before the abnormality detection signal S51 is output by the abnormality determination unit 51. When the abnormality detection signal S51 is output by the abnormality determination unit 51, the abnormality control execution unit 532 is selected by the abnormality control selection unit 531 from the three-phase short-circuit control and the fully open control. It may be configured to perform the controlled control.

In the description of the third, fourth and fifth embodiments, the control unit 50 (normal control unit 52 and abnormality control unit 53) acquires the rotation speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. Although the case has been given as an example, the motor control device 40 may be provided with a rotation speed sensor (not shown) for detecting the rotation speed of the motor 3. The control unit 50 (normal control unit 52 and abnormality control unit 53) may be configured to acquire the rotation speed of the motor 3 by inputting the rotation speed detected by the rotation speed sensor.

Further, embodiments 3, 4, 5 and modified examples may be appropriately combined, and further, embodiments 1, 2 and modified examples may be appropriately combined.

For example, the motor control device 40 according to the third, fourth, and fifth embodiments has a three-phase short-circuit control device that has been selected in advance according to the operating state of the motor 3 when the abnormality determination unit 31 determines that there is an abnormality. After performing the fully open control, either the three-phase short-circuit control or the fully open control may be further performed according to the torque acting on the motor 3 as the abnormal continuation response operation described in the first and second embodiments.

The above embodiments are essentially preferred embodiments and are not intended to limit the scope of the invention, its applications, or its uses.

As described above, this disclosure is useful as a motor control device.

10, 40 Motor control device 2 DC power supply 3 Motor 11 Inverter 12 Smoothing capacitor 20 Sensor 21u ~ 21w Current sensor 22 Pole position sensor 30, 50 Control unit 31, 51 Abnormality determination unit 32 Switching control unit 33 Operation control unit 52 Normal control unit 53 Abnormality control unit 531 Abnormality control selection unit 532 Abnormality control execution unit 55 Control processing unit LP Power supply line LG Ground line LOu to LOw Output line

Claims (13)

A motor control device that controls a three-phase AC motor using the power of a DC power supply.
Three high-side switching elements connected between the three output lines connected to the three input terminals of the motor and the power supply line connected to the positive electrode of the DC power supply, respectively.
An inverter having three low-side switching elements connected between the three output lines and a ground wire connected to the negative electrode of the DC power supply, respectively.
A sensor that detects information used to control the switching operation of the inverter, and
With a control unit,
The control unit
An abnormality determination is made for at least one of the DC power supply, the motor, the inverter, and the sensor.
Until it is determined that there is an abnormality by the abnormality determination, normal control for controlling the switching operation of the inverter is performed based on the information detected by the sensor.
From the high-side switching element group composed of the three high-side switching elements and the three low-side switching elements according to the torque acting on the motor during the abnormality continuation period after the abnormality determination determines that there is an abnormality. Three-phase short circuit control that turns one switching element group on and the other switching element group off, and turns off the high-side switching element group and all of the low-side switching element group. have line either the fully open control to,
The control unit further
An abnormality determination unit that determines an abnormality in the DC power supply, the motor, the inverter, and the sensor.
Normally, the switching operation of the inverter is controlled based on the information detected by the sensor until at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination unit. Control unit and
Has an anomaly control unit,
The abnormality control unit
Before the DC power supply, the motor, the inverter, and at least one of the sensors are determined to be abnormal by the abnormality determination unit, the three-phase short-circuit control and the fully open control are performed according to the operating state of the motor. Anomaly control selection unit that selects one of the
When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination unit, the abnormality control selection unit selects between the three-phase short-circuit control and the fully open control. Has an anomaly control execution unit that performs controlled control,
Motor control device. The control unit
An abnormality determination unit that determines an abnormality in at least one of the DC power supply, the motor, the inverter, and the sensor.
A switching control unit that performs the normal control, the three-phase short-circuit control, and the fully open control,
The switching control unit is made to perform the normal control until the abnormality determination unit determines that there is an abnormality, and the three-phase short-circuit control and the fully open control are performed according to the torque acting on the motor during the abnormality continuation period. It has an operation control unit that causes the switching control unit to perform either one.
The motor control device according to claim 1. The abnormality determination unit is composed of hardware separate from the switching control unit and the operation control unit, and determines that at least one of the DC power supply, the motor, the inverter, and the sensor has an abnormality. An abnormality detection signal is output to the operation control unit.
The motor control device according to claim 2. The operation control unit is configured by hardware separate from the switching control unit, and switches a control signal for performing one of the normal control, the three-phase short-circuit control, and the fully open control. Output to the control unit,
The motor control device according to claim 2 or 3. The control unit terminates the three-phase short-circuit control when the torque acting on the motor falls below a predetermined first torque threshold when the three-phase short-circuit control is performed during the abnormal continuation period. When the full-open control is started and the torque acting on the motor exceeds a predetermined second torque threshold when the full-open control is performed, the full-open control is terminated and the three-phase short-circuit control is performed. To start,
The motor control device according to any one of claims 1 to 4. The sensor includes a current sensor that detects a phase current flowing through the motor and a magnetic pole position sensor that detects the magnetic pole position of the motor.
The control unit acquires the torque acting on the motor based on the phase current detected by the current sensor and the magnetic pole position detected by the magnetic pole position sensor.
The motor control device according to any one of claims 1 to 5. The control unit
In the normal control, field weakening control is performed on the motor according to the rotation speed of the motor.
When it is determined that there is an abnormality by the abnormality determination, either the three-phase short-circuit control or the fully open control is performed depending on whether or not the field weakening control is performed on the motor and at least one of the rotation speeds of the motor. conduct,
The motor control device according to any one of claims 1 to 6. The abnormality determination unit is composed of hardware separate from the normal control unit and the abnormality control unit, and it is determined that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. Output the detection signal and
The normal control unit controls the switching operation of the inverter based on the information detected by the sensor until the abnormality detection signal is output by the abnormality determination unit.
When the abnormality detection signal is output by the abnormality determination unit, the abnormality control unit selects either one of the three-phase short-circuit control and the fully open control according to the operating state of the motor.
The motor control device according to claim 1. The abnormality determination unit determines whether or not the switching element is a short-circuit abnormality that is always on for each of the three high-side switching elements and the three low-side switching elements.
In the three-phase short-circuit control, the abnormality control unit turns on a switching element group including a switching element determined to be a short-circuit abnormality by the abnormality determination unit among the high-side switching element group and the low-side switching element group. It is configured to be in a state,
The motor control device according to claim 1. The abnormality determination unit is configured to determine for each of the three high-side switching elements and the three low-side switching elements whether or not the switching element is an open abnormality that is always in an off state.
In the three-phase short-circuit control, the abnormality control unit turns off the switching element group including the switching element determined to be the opening abnormality among the high-side switching element group and the low-side switching element group by the abnormality determination unit. It is configured to be in a state,
The motor control device according to claim 1. A motor control device that controls a three-phase AC motor using the power of a DC power supply.
Three high-side switching elements connected between the three output lines connected to the three input terminals of the motor and the power supply line connected to the positive electrode of the DC power supply, and the three output lines. An inverter having three low-side switching elements connected to the ground wire connected to the negative electrode of the DC power supply, respectively.
A sensor that detects information used to control the switching operation of the inverter, and
An abnormality determination unit that determines an abnormality in the DC power supply, the motor, the inverter, and the sensor.
Normally, the switching operation of the inverter is controlled based on the information detected by the sensor until at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination unit. Control unit and
When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination unit, a high composed of the three high-side switching elements is determined according to the operating state of the motor. Three-phase short-circuit control and the high-side switching element that turn on one switching element group of the side switching element group and the low-side switching element group consisting of the three low-side switching elements and turn the other switching element group off. It is provided with an abnormality control unit that selects and performs either a group or a fully open control that turns off the entire group and the low-side switching element group.
The abnormality control unit
Before the DC power supply, the motor, the inverter, and at least one of the sensors are determined to be abnormal by the abnormality determination unit, the three-phase short-circuit control and the fully open control are performed according to the operating state of the motor. Anomaly control selection unit that selects one of the
When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination unit, the abnormality control selection unit selects between the three-phase short-circuit control and the fully open control. It has an abnormality control execution unit that performs controlled control.
Motor control device. Three high-side switching elements connected between three output lines connected to each of the three input terminals of a three-phase AC motor and a power supply line connected to the positive electrode of a DC power supply, and the three. An inverter having three low-side switching elements connected between an output line and a ground line connected to the negative electrode of the DC power supply, and a sensor for detecting information used for controlling the switching operation of the inverter. It is a control method of the equipped motor control device.
An abnormality determination step for determining an abnormality in at least one of the DC power supply, the motor, the inverter, and the sensor.
A normal control step that controls the switching operation of the inverter based on the information detected by the sensor until it is determined that there is an abnormality by the abnormality determination step.
A high-side switching element group composed of the three high-side switching elements and the three low-side switching elements according to the torque acting on the motor during the abnormality continuation period after the abnormality is determined by the abnormality determination step. Three-phase short-circuit control that turns one switching element group on and the other switching element group off, and turns off all of the high-side switching element group and the low-side switching element group. Including an abnormal continuation response step that performs either one of the full open control to make the state.
Including anomaly control steps
The abnormality control step is
Before the DC power supply, the motor, the inverter, and at least one of the sensors are determined to be abnormal by the abnormality determination step, the three-phase short-circuit control and the fully open control are performed according to the operating state of the motor. Anomaly control selection step to select one of the
When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination step, the abnormality control selection step of the three-phase short circuit control and the fully open control is used. Including anomalous control execution steps that perform the selected control,
Control method of motor control device. Three high-side switching elements connected between three output lines connected to each of the three input terminals of a three-phase AC motor and a power supply line connected to the positive electrode of a DC power supply, and the three. An inverter having three low-side switching elements connected between an output line and a ground line connected to the negative electrode of the DC power supply, and a sensor for detecting information used for controlling the switching operation of the inverter. It is a control method of the equipped motor control device.
An abnormality determination step for determining an abnormality with respect to the DC power supply, the motor, the inverter, and the sensor.
When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal in the abnormality determination step, it is composed of the three high-side switching elements according to the operating state of the motor. Three-phase short-circuit control and high-side switching in which one of the high-side switching element group and the low-side switching element group consisting of the three low-side switching elements is turned on and the other switching element group is turned off. It includes an abnormality control step in which either one of the element group and the fully open control for turning off the entire low-side switching element group is selected and performed.
The abnormality control step is
Before the DC power supply, the motor, the inverter, and at least one of the sensors are determined to be abnormal by the abnormality determination step, the three-phase short-circuit control and the fully open control are performed according to the operating state of the motor. Anomaly control selection step to select one of the
When at least one of the DC power supply, the motor, the inverter, and the sensor is determined to be abnormal by the abnormality determination step, the abnormality control selection step of the three-phase short circuit control and the fully open control is used. Including anomalous control execution steps that perform the selected control,
Control method of motor control device.

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