JP2019122238A - Motor control device and control method thereof - Google Patents

Abstract

To effectively suppress both the rapid deceleration of a motor and the overvoltage of a power line connecting a DC power supply and an inverter.SOLUTION: A control unit 30 performs abnormality determination on at least one of a DC power supply 2, a motor 3, an inverter 11, and a sensor 20. Further, the control unit 30 controls one of three-phase short circuit control in which one of high side switching element groups S1, S2, and S3 and low side switching element groups S4, S5, and S6 is turned on, and the other is turned off according to a torque acting on the motor 3 in an abnormal continuation period after it is determined that there is an abnormality by abnormal determination, and fully-open control in which all of the high side switching element groups S1, S2 and S3 and the low side switching element groups S4, S5, and S6 are turned off.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a motor control device and a control method of the motor control device.

  BACKGROUND Conventionally, motor control devices that control a motor by the power of a DC power supply are known. As an example of such a motor control device, Patent Document 1 discloses an electric system of an electric car that uses a battery as a power source and drives a permanent magnet type synchronous motor for driving a vehicle via a voltage source inverter. In the electric system of this electric vehicle, synchronization is achieved by collectively turning on the switching elements of the upper arm or lower arm of the inverter when an abnormality occurs such as opening of the DC circuit from the battery to the inverter while the vehicle is traveling. The input terminal of the motor is shorted to stop the power supply from the inverter.

Japanese Patent Application Laid-Open 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, when the rotation speed of the synchronous motor decreases while an abnormality occurs and control is performed to turn on the switching elements of the upper arm or the lower arm of the inverter collectively, The regenerative torque acting on the synchronous motor may cause the rotational speed of the synchronous motor to rapidly decrease. In addition, it is possible to perform control of turning off all the switching elements of an inverter, when abnormality generate | occur | produces. However, when the rotational speed of the synchronous motor rises while control is performed to turn off all the switching elements of the inverter due to an abnormality occurring, the power is regenerated by the power regenerated from the synchronous motor to the battery via the inverter. There is a possibility that the power line connecting the two and the inverter becomes an overvoltage (for example, a voltage exceeding the legal regulation voltage). As described above, in the electrical system of Patent Document 1, it is difficult to suppress both the rapid deceleration of the synchronous motor and the overvoltage of the power line connecting the power supply and the inverter.

  Therefore, the present disclosure provides a motor control device that can be further improved.

  The present disclosure relates to a motor control device for controlling a three-phase AC motor by the power of a DC power supply, and the motor control device comprises three output lines respectively connected to three input terminals of the motor and the DC power supply. Three high-side switching devices respectively connected between power supply lines connected to the positive electrode, and three connected between the three output lines and a ground line connected to the negative electrode of the DC power supply An inverter having a low side switching element, a sensor that detects information used to control the switching operation of the inverter, and a control unit are provided. The control unit performs abnormality determination on at least one of the DC power supply, the motor, the inverter, and the sensor, and the information detected by the sensor until it is determined that the abnormality is determined by the abnormality determination. Normal control to control the switching operation of the inverter based on the three high-side switching according to the torque acting on the motor in an abnormal continuation period after it is determined that there is an abnormality by the abnormality determination. Three-phase short circuit control for turning on one of the high side switching element group consisting of elements and the low side switching element group consisting of the three low side switching elements while turning on the other switching element group High side switching element group and low side switch Performing either fully open control of the whole of the quenching element group off.

  In addition, this disclosure relates to three high-side switchings respectively connected between three output lines respectively connected to three input terminals of a three-phase AC motor and a power supply line connected to a positive electrode of a DC power supply. An inverter having an element, three low-side switching elements respectively connected between the three output lines and a ground line connected to the negative electrode of the DC power supply, and information used to control the switching operation of the inverter Control method of a motor control device including a sensor for detecting a motor control device, the control method of the motor control device includes an abnormality for performing abnormality determination on at least one of the DC power supply, the motor, the inverter, and the sensor Based on the information detected by the sensor until it is determined that there is an abnormality in the determination step and the abnormality determination step. It consists of the three high-side switching elements according to the torque that acts on the motor in the normal control step that controls the switching operation of the converter and in the abnormal continuation period after the abnormality determination step determines that there is an abnormality. Three-phase short-circuit control for turning on one switching element group of the high-side switching element group and the low-side switching element group consisting of the three low-side switching elements and turning off the other switching element group And an abnormal continuation handling step of performing any one of an element group and a full open control for turning off all of the low side switching element group.

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

FIG. 1 is a block diagram illustrating the configuration of a motor control device according to a first embodiment. It is a block diagram which illustrates the composition of a switching control part. It is a graph which illustrates the relation between torque and rotation speed in three-phase short circuit control. It is a graph which illustrates the relation between torque and rotation speed in full release control. 6 is a flowchart illustrating switching operation of field weakening control; 5 is a flowchart illustrating an abnormality occurrence handling operation. It is a flowchart which illustrates abnormal continuation corresponding operation. FIG. 6 is a block diagram illustrating the configuration of a motor control device according to a second embodiment. FIG. 10 is a block diagram illustrating the configuration of a motor control device according to a third embodiment. It is a flowchart which illustrates the details of three phase short circuit control. FIG. 10 is a block diagram illustrating the configuration of a motor control device according to a fourth embodiment. 15 is a flowchart illustrating an operation of the abnormality control selection unit of the fourth embodiment. 15 is a flowchart illustrating an operation of the abnormality control execution unit of the fourth embodiment. FIG. 13 is a block diagram illustrating the configuration of a motor control device according to a fifth embodiment.

  A motor control device according to an aspect of the present disclosure is a motor control device that controls a three-phase AC motor by power of a DC power source, and includes three output lines respectively connected to three input terminals of the motor The three high-side switching elements respectively connected between the power supply line connected to the positive electrode of the DC power supply, and the ground lines connected to the three output lines and the negative electrode of the DC power supply An inverter having three low-side switching elements, a sensor that detects information used to control the switching operation of the inverter, and a control unit. The control unit performs abnormality determination on at least one of the DC power supply, the motor, the inverter, and the sensor, and the information detected by the sensor until it is determined that the abnormality is determined by the abnormality determination. Normal control to control the switching operation of the inverter based on the three high-side switching according to the torque acting on the motor in an abnormal continuation period after it is determined that there is an abnormality by the abnormality determination. Three-phase short circuit control for turning on one of the high side switching element group consisting of elements and the low side switching element group consisting of the three low side switching elements while turning on the other switching element group High side switching element group and low side switch Performing either fully open control of the whole of the quenching element group off.

  Thereby, the rapid deceleration of the motor and the overvoltage of the power line connecting the DC power supply and the inverter are performed by performing either one of the three-phase short circuit control and the full open control according to the torque acting on the motor in the abnormal continuation period. Can be effectively suppressed.

  Further, the control unit is an abnormality determination unit that performs abnormality determination on at least one of the DC power supply, the motor, the inverter, and the sensor, the normal control, the three-phase short circuit control, and the all open control. And the switching control unit to perform the normal control until it is determined that there is an abnormality by the abnormality determining unit, and the three-phase control is performed according to the torque acting on the motor in the abnormality continuation period. You may have the operation control part which makes the said switching control part perform either short circuit control and this all open control.

  Thereby, both the rapid deceleration of the motor and the overvoltage of the power line connecting the DC power supply and the inverter are 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.

  Further, the abnormality determination unit is configured by hardware separate from the switching control unit and the operation control unit, and there is an abnormality in at least one of the DC power supply, the motor, the inverter, and the sensor. If determined, an abnormality detection signal may be output to the operation control unit.

  Thus, by configuring the abnormality determination unit by hardware, it is possible to perform the abnormality determination in the abnormality determination unit more quickly than when configuring the abnormality determination unit by software.

  The operation control unit is configured by hardware separate from the switching control unit, and a control signal for performing any one of the normal control, the three-phase short circuit control, and the all open control is used. You may output to this switching control part.

  Thus, by configuring the operation control unit with hardware, the operation control unit can control the switching control unit more quickly than when configuring the operation control unit with software.

  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 in the abnormal continuation period. And when the torque acting on the motor exceeds a predetermined second torque threshold when the full open control is being performed, the full open control is terminated and the three-phase operation is started. Short circuit control may be started.

  Thereby, the rapid deceleration of the motor and the overvoltage of the power line connecting the DC power supply and the inverter are performed by alternately switching the three-phase short circuit control and the full open control according to the torque acting on the motor in the abnormal continuation period. Both can be effectively suppressed.

  Further, the sensor includes a current sensor that detects a phase current flowing in the motor, and a magnetic pole position sensor that detects a magnetic pole position of the motor, and the control unit detects 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.

  The control unit performs field weakening control on the motor according to the rotational speed of the motor in the normal control, and when it is determined that there is an abnormality by the abnormality determination, the field weakening control for the motor is performed. Either the three-phase short circuit control or the full open control may be performed according to at least one of the presence or absence of the operation and the rotational speed of the motor.

  Thus, it is possible to appropriately perform control according to at least one of the presence / absence of the field weakening control on the motor and the rotational speed of the motor among the three phase short circuit control and the full open control.

  In addition, the control unit performs abnormality determination on the DC power supply, the motor, the inverter, and the sensor, and the abnormality determination unit determines the DC power supply, the motor, the inverter, and the sensor. The abnormality control unit includes a normal control unit that controls the switching operation of the inverter based on the information detected by the sensor until it is determined that at least one is abnormal, and the abnormality control unit Before the abnormality determination unit determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal, the three-phase short circuit control and the all open according to the operation state of the motor And an abnormality control selection unit for selecting one of the control and the DC power supply, the motor, the inverter, and the sensor by the abnormality determination unit. If it is determined that at least one is abnormal, it may have an abnormal control execution unit that performs control selected by the abnormal control selection unit among the three-phase short circuit control and the all open control. .

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

  Further, the abnormality determination unit is configured by hardware separate from the normal control unit and the abnormality control unit, and determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. Then, an 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 unit outputs the abnormality detection signal, and the abnormality is detected. When the abnormality detection unit outputs the abnormality detection signal, the control unit may select one of the three-phase short circuit control and the full release control according to the operation state of the motor.

  Thereby, when it is determined that there is an abnormality by the abnormality determination, the operation state of the motor (specifically, whether or not the field weakening control is performed on the motor and the rotational speed of the motor) among the three phase short circuit control and the all open control. The control according to at least one of them can be appropriately performed.

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

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

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

  Thereby, even when the open 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 performed normally.

  A motor control device according to an aspect of the present disclosure is a motor control device that controls a three-phase AC motor by power of a DC power source, and includes three output lines respectively connected to three input terminals of the motor The three high-side switching elements respectively connected between the power supply line connected to the positive electrode of the DC power supply, and the ground lines connected to the three output lines and the negative electrode of the DC power supply An abnormality having an inverter having three low side switching elements, a sensor for detecting information used to control a switching operation of the inverter, the DC power supply, the motor, the inverter, and the sensor At least one of the DC power supply, the motor, the inverter, and the sensor is abnormal by the abnormality determination unit and the abnormality determination unit. And the abnormality determination unit controls at least one of the DC power supply, the motor, the inverter, and the sensor until the determination is made that the controller determines the switching operation of the inverter based on the information detected by the sensor. If it is determined that one is abnormal, 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 operating state of the motor One of three-phase short-circuit control in which the switching element group is turned on and the other switching element group is turned off, and all open control in which the high side switching element group and the low side switching element group are all turned off. And an anomaly control unit to perform There. The three-phase short circuit according to the operation state of the motor before the abnormality control unit determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal by the abnormality determination unit. If an abnormality control selection unit that selects any one of control and the full release control, and if the abnormality determination unit determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal, An abnormal control execution unit performing control selected by the abnormal control selection unit among the three-phase short circuit control and the all open control.

  Thus, either one of the three-phase short circuit control and the full release control can be selected according to the operation state of the motor before it is determined by the abnormality determination unit that there is an abnormality. If it is determined that the three phase short circuit control or the full open control can be performed quickly.

  A control method of a motor control device according to an aspect of the present disclosure includes: between three output lines respectively connected to three input terminals of a three-phase AC motor and a power supply line connected to a positive electrode of a DC power supply. An inverter having three high side switching elements connected respectively, three low side switching elements respectively connected between the three output lines and a ground line connected to the negative electrode of the DC power supply, and the inverter A control method of a motor control device comprising: a sensor for detecting information used for control of the switching operation of at least one of the DC power supply, the motor, the inverter, and the sensor. The abnormality determination step to be performed and the determination based on the information detected by the sensor until the abnormality determination step determines that there is an abnormality. It consists of the three high-side switching elements according to the torque that acts on the motor in the normal control step that controls the switching operation of the converter and in the abnormal continuation period after the abnormality determination step determines that there is an abnormality. Three-phase short-circuit control for turning on one switching element group of the high-side switching element group and the low-side switching element group consisting of the three low-side switching elements and turning off the other switching element group And an abnormal continuation handling step of performing any one of an element group and a full open control for turning off all of the low side switching element group.

  Thereby, the rapid deceleration of the motor and the overvoltage of the power line connecting the DC power supply and the inverter are performed by performing either one of the three-phase short circuit control and the full open control according to the torque acting on the motor in the abnormal continuation period. Can be effectively suppressed.

  Further, the control method of the motor control device further includes an abnormality control step, wherein at the abnormality control step, at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal at the abnormality determination step. An abnormal control selection step of selecting any one of the three-phase short circuit control and the full release control according to the operation state of the motor before it is determined, and the DC power supply, the motor and the motor according to the abnormality determination step An abnormal control execution step of performing control selected in the abnormal control selection step among the three-phase short circuit control and the all open control when it is determined that at least one of the inverter and the sensor is abnormal; It may further include.

  Thus, in addition to performing control according to the torque acting on the motor among the three-phase short circuit control and the full release control, three are performed according to the operation state of the motor before it is determined that there is an abnormality in the abnormality determination step. Since either one of the phase short circuit control and the all open control can be selected, the three phase short circuit control or the all open control can be quickly performed when it is determined in the abnormality determination step that there is an abnormality.

  A control method of a motor control device according to an aspect of the present disclosure includes: between three output lines respectively connected to three input terminals of a three-phase AC motor and a power supply line connected to a positive electrode of a DC power supply. An inverter having three high side switching elements connected respectively, three low side switching elements respectively connected between the three output lines and a ground line connected to the negative electrode of the DC power supply, and the inverter Method of controlling a motor control apparatus comprising a sensor for detecting information used for controlling the switching operation of the motor, wherein the abnormality determination step performs abnormality determination on the DC power supply, the motor, the inverter, and the sensor And 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. If 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 is turned on in accordance with the operation state of the motor. Select either one of three-phase short-circuit control to turn off the other switching element group while putting in the state, and full open control to turn off all of the high side switching element group and the low side switching element group An abnormality control step, wherein the abnormality control step operates the motor before 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 three-phase short circuit control and the all open according to the state The three-phase short circuit when an abnormality control selection step of selecting any one of the above and the abnormality determination step determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. And an abnormal control execution step of performing control selected by the abnormal control selection step among the control and the all open control.

  Thereby, either one of the three-phase short circuit control and the full release control can be selected according to the operation state of the motor before it is determined in the abnormality determination step that there is an abnormality. If it is determined that the three phase short circuit control or the full open control can be performed quickly.

  Embodiments will be specifically described below with reference to the drawings.

  The embodiments described below are all inclusive or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are merely examples, and the present invention is not limited thereto. Further, among the components in the following embodiments, components not described in the independent claim indicating the highest concept are described as arbitrary components. Further, each drawing is a schematic view, and is not necessarily illustrated exactly. Moreover, in each figure, the same code | symbol is attached | subjected about the same structural member.

(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 a three-phase AC motor 3 by the power of the DC power supply 2. In this example, the motor 3 is configured to drive drive wheels (not shown) of the electric vehicle. The electric vehicle is provided with a power transmission mechanism (not shown) for transmitting power between the motor 3 and the drive wheels. The power transmission mechanism is constituted by, 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 to this, the rotational force of the drive wheel 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 passing through the power transmission mechanism.

  Further, in this example, the motor 3 is configured by a permanent magnet motor. For example, the motor 3 is configured by an embedded magnet synchronous motor (IPMSM), a surface magnet synchronous motor (SPMSM), or the like. The motor 3 may be configured by a brushless motor. The DC power supply 2 may be configured by, 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 DC power supplied from the DC power supply 2 into three-phase AC power by switching operation and to supply the AC power to the motor 3. Specifically, the inverter 11 includes three high side switching elements (first, second and third high side switching elements S1, S2 and S3) and three low side switching elements (first, second and third elements). And low side switching elements S4, S5 and S6).

  Three high side switching elements S1 to S3 are three output lines (first, second and third output lines LOu, LOv, LOw) respectively connected to three input terminals of motor 3 and a positive electrode of DC power supply 2 Are respectively connected to the power supply line LP connected to. For example, the high side switching elements S1 to S3 are configured by a field effect transistor (FET), an insulated gate bipolar transistor (IGBT), or the like. The high side switching elements S1 to S3 may be configured using wide band gap semiconductors.

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

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

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

[Sensor]
The sensor 20 is configured to detect information used to control the switching operation of the inverter 11. In this example, the motor control device 10 includes three current sensors (first, second and third current sensors 21 u, 21 v, 21 w) respectively 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 21 u to 21 w are configured to respectively detect three phase currents (U-phase current iu, V-phase current iv, and W-phase current iw) flowing to the motor 3. For example, the current sensors 21 u to 21 w are configured by shunt resistors.

  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 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 an arithmetic processing unit such as a CPU, a storage unit such as a memory that stores programs and information for operating the arithmetic processing unit, and supplies switching signals to the switching elements S1 to S6 to perform switching. It is comprised by drive circuits, such as gate drive IC which controls on-off of element S1-S6.

  In this example, the control unit 30 includes the phase currents iu to iw detected by the current sensors 21 u to 21 w, 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 the electric vehicle) is input.

  Further, the control unit 30 performs 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 control unit 30 performs abnormality determination on 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 that there is an abnormality by the abnormality determination. In the 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 from various sensors such as the current sensors 21 u to 21 w and the magnetic pole position sensor 22 (specifically, 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 .theta.e of the motor 3, respectively.

  In this example, the control unit 30 is configured to perform field weakening control on the motor 3 in accordance with the rotational speed of the motor 3 in normal control. Specifically, when the rotational speed of motor 3 exceeds the predetermined high rotation threshold in normal control, control unit 30 executes field weakening control on motor 3 and the rotational speed of motor 3 is high. If the rotation threshold value is not exceeded, field weakening control is not performed on the motor 3. The high rotation threshold is set to a rotational speed lower than the rotational speed of the motor 3 when the back 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 obtain 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 rotational speed of the motor 3 by differentiating the magnetic pole position θe detected by the magnetic pole position sensor 22.

  Further, when it is determined that there is an abnormality in the abnormality determination, the control unit 30 performs either one of the three-phase short circuit control and the full open control according to the operation state of the motor 3. In the three-phase short circuit control, the control unit 30 selects one of the high side switching element group including three high side switching elements S1 to S3 and the low side switching element group including three low side switching elements S4 to S6. At the same time, the other switching element group is turned off. In the full open control, the control unit 30 turns off all of the high side switching element group including three high side switching elements S1 to S3 and the low side switching element group including three low side switching elements S4 to S6.

  In this example, when it is determined that there is an abnormality based on the abnormality determination, control unit 30 performs three-phase short circuit control and full opening according to at least one of the presence or absence of field weakening control for motor 3 and the rotational speed of motor 3. It is configured to perform any one of the controls. Specifically, control unit 30 performs three-phase short circuit control when field weakening control is performed on motor 3 or when the rotational speed of motor 3 exceeds a predetermined rotational speed threshold, and control unit 30 performs control on motor 3. When the field weakening control is not performed and the rotational speed of the motor 3 does not exceed the rotational speed threshold value, the full opening control is performed. The rotation speed threshold may be the same rotation speed as the high rotation threshold (the rotation speed serving as a criterion for determining whether or not field-weakening control needs to be performed), or may be a rotation speed different from the high rotation threshold. .

  Further, in a period (abnormality continuation period) after it is determined that there is an abnormality by the abnormality determination, control unit 30 performs either one of the three-phase short circuit control and the totally open control according to torque Tet acting on motor 3. Do. Specifically, in the abnormal continuation period, when three-phase short circuit control is performed, control unit 30 determines that three-phase short circuit occurs when torque Tet acting on motor 3 falls below predetermined first torque threshold Tth1. End control and start all release control. Further, when the torque Tet acting on the motor 3 exceeds the predetermined second torque threshold Tth2 while the full opening control is performed in the abnormal continuation period, the control unit 30 ends the full opening control. Start three-phase short circuit control. The first torque threshold Tth1 and the second torque threshold Tth2 will be described in detail later.

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

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

[Configuration of control unit]
As shown in FIG. 1, in this example, the control unit 30 includes 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 configure 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 performs abnormality determination on 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 abnormality of the DC power supply 2, the motor 3, the inverter 11, and the sensor 20 as follows.

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

<Abnormal judgment of motor and inverter>
Further, abnormality determination unit 31 receives phase currents iu to iw detected by current sensors 21 u to 21 w, and determines abnormality of motor 3 and inverter 11 based on phase currents iu to iw. Specifically, abnormality determination unit 31 detects the phase difference between the three phase currents iu to iw when it 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 receives the output of the sensor 20 (in this example, the current sensors 21 u to 21 w and the magnetic pole position sensor 22), and determines the abnormality of the sensor 20 based on the output of the sensor 20. Specifically, 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, the abnormality determination unit 31 sends the error to the sensor 20. Determine that there is an abnormality. Generally, when an abnormality such as disconnection occurs in the sensor 20, the output of the sensor 20 becomes constant at the maximum level (or the minimum level).

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

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

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

  Further, abnormality determination unit 31 determines that the difference between U-phase voltage Vu corresponding to first low side switching element S4 and ground voltage VG has an abnormal value (for example, the first value during the period in which first low side switching element S4 should be turned off). When the low side switching element S4 is in the off state, the first low side switching element S4 has a short circuit abnormality if 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 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 in a period in which the first low side switching element S4 should be turned off, the first low side switching It is determined that the element S4 is not short circuited. 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 with respect to the six switching elements S1 to S6. Specifically, when there is a switching element determined to be a short circuit abnormality among the six switching elements S1 to S6, the abnormality determination unit 31 determines that the inverter 11 has an abnormality.

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

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

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

  Further, abnormality determination unit 31 determines that the difference between U-phase voltage Vu corresponding to first low side switching element S4 and ground voltage VG has an abnormal value (for example, the first value during the period in which first low side switching element S4 should be turned on). When the low side switching element S4 is in the ON state, the first low side switching element S4 has an open abnormality if 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 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 in a period in which the first low side switching element S4 should be turned off, the first low side switching 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 open abnormality with respect to the six switching elements S1 to S6. Specifically, when there is a switching element determined to be an open abnormality among the six switching elements S1 to S6, the abnormality determination unit 31 determines that the inverter 11 has an abnormality.

[Switching control unit]
The switching control unit 32 is configured to perform normal control, three-phase short circuit control, and full open control. The switching control unit 32 is configured to perform field weakening control on the motor 3 in accordance with the rotational speed of the motor 3 in normal control. Specifically, when the rotational speed of the motor 3 exceeds the high rotational speed threshold in the normal control, the switching control unit 32 performs field weakening control on the motor 3 and the rotational speed of the motor 3 has a high rotational speed threshold. When not exceeding, 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 generates 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 21 u to 21 w and the magnetic pole position θe detected by the magnetic pole position sensor 22. To derive.

  Current command generation unit 302 derives d-axis current command value id * and q-axis current command value iq * based on torque command Te. Specifically, current command generation unit 302 multiplies torque command Te by a sine value (sin θ) to derive d-axis current command value id *, and multiplies torque command Te by cosine value (cos θ) to q The axis current command value iq * is derived.

  The current control unit 303 uses the d-axis current id and the q-axis current iq derived by the coordinate conversion unit 301 and the d-axis current command value id * and the 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 * become smaller. The axis voltage command value Vd * and the q-axis voltage command value Vq * are derived.

  The coordinate inverse transformation unit 304 determines the 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 generates 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. Generate six gate signals respectively supplied to Specifically, the PWM signal generation unit 305 performs PWM control of 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 the necessity of implementation of field weakening control based on the rotational speed of the motor 3. Specifically, the field weakening control unit 306 determines that the field weakening control needs to be performed when the rotational speed of the motor 3 exceeds the high revolution threshold value, and the rotational speed of the motor 3 does not exceed the high revolution threshold value. It is determined that implementation of field weakening control is unnecessary. When field weakening control is performed, the field weakening control unit 306 controls the operation of the current command generation unit 302 such 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 cancels 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 obtain the rotational 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 (normal operation) that is performed until it is determined that there is an abnormality by abnormality determination, and an operation that is performed when it is determined that there is an abnormality (error occurrence handling operation And an operation (abnormal continuation corresponding operation) performed in a period (abnormal continuation period) after it is determined that there is an abnormality 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.

<Error occurrence response operation>
In addition, when the abnormality determination unit 31 determines that there is an abnormality, the operation control unit 33 causes the switching control unit 32 to perform either one of the three-phase short circuit control and the all open control according to the operation state of the motor 3. Is configured as. In this example, when the operation control unit 33 determines that there is an abnormality by the abnormality determination unit 31, three-phase short circuit control is performed according to at least one of the presence or absence of execution of field weakening control on the motor 3 and the rotational speed of the motor 3. It is configured to cause the switching control unit 32 to perform either one or all open control. Specifically, the operation control unit 33 performs three-phase short circuit control on the switching control unit 32 when field weakening control is performed on the motor 3 or when the rotational speed of the motor 3 exceeds a predetermined rotational speed threshold. In the case where field weakening control on the motor 3 is not performed and the rotational speed of the motor 3 does not exceed the rotational speed threshold, the switching control unit 32 is configured to perform full open control.

<Abnormal continuation corresponding operation>
In addition, in a period (abnormality continuation period) after the operation control unit 33 determines that there is an abnormality by the abnormality determination unit 31, either of the three-phase short circuit control and the all 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, when the torque Tet acting on the motor 3 falls below the first torque threshold Tth1 while the three-phase short circuit control is being performed during the abnormal continuation period, the operation control unit 33 causes the switching control unit 32 to The operation of the switching control unit 32 is controlled to end the phase short circuit control and start the all open control. Further, in the abnormal continuation period, when the torque Tet acting on the motor 3 exceeds the second torque threshold Tth2 in the abnormal continuation period while the full opening control is performed, the switching control unit 32 ends the full opening control. The operation of the switching control unit 32 is controlled to start three-phase short circuit control.

  In this example, the operation control unit 33 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. In addition, the operation control unit 33 obtains (estimates) the torque Tet acting on the motor 3 based on the phase currents iu to iw detected by the current sensors 21 u to 21 w and the magnetic pole position θe detected by the magnetic pole position sensor 22. Is configured as. 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 rotational 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. The regenerative torque is a torque having a negative value (that is, a torque acting in the opposite direction to the rotational direction of the motor 3), and as shown in FIG. 3, as the rotational speed of the motor 3 decreases, the motor The absolute value of the torque Tet (regeneration torque having a negative value) acting on 3 tends to gradually increase. Therefore, when the rotational 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 (a torque Tet having a negative value) acting on the motor 3 The rotational speed of the motor 3 may be rapidly reduced.

  In the example of FIG. 3, when the rotational speed of the motor 3 falls below the first rotational speed R1, the absolute value of the torque Tet (regenerative torque having a negative value) acting on the motor 3 with respect to the reduction of the rotational speed of the motor 3 increases. Ratio (rate of increase of regenerative torque) is high. In this example, the first torque threshold Tth1 serving as the determination reference for switching from the three-phase short circuit control to the full release control is applied when the rotational speed of the motor 3 is the first rotational speed R1 (ie, acts on the motor 3) It is set to the value of the torque acting on the motor 3 when it can be considered that the increasing rate of the regenerative torque becomes high.

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

  Incidentally, when the induced voltage of the motor 3 increases with the increase of the rotational speed of the motor 3 and the induced voltage of the motor 3 exceeds the voltage of the DC power supply 2, as shown in FIG. growing. In the example of FIG. 4, when the rotational speed of the motor 3 exceeds the second rotational speed R2, the torque Tet acting on the motor 3 increases. In this example, the second torque threshold Tth2 serving as the determination reference for switching from full open control to three-phase short circuit control is when the rotational speed of the motor 3 is the second rotational speed (ie, the induced voltage of the motor 3 is When it is considered that the voltage of the DC power supply 2 is exceeded, the value of the torque acting on the motor 3 is set.

  Further, as shown in FIG. 4, when the rotational speed of the motor 3 exceeds the second rotational speed R2, the torque Tet acting on the motor 3 largely fluctuates. As a result, if the vehicle speed of the electric vehicle is increased due to a downhill or the like while the full release control is performed, and the rotational speed of the motor 3 is increased, vibrations due to the fluctuation of the torque Tet occur in the electric vehicle. Therefore, in order to avoid the vibration, the second torque threshold Tth2 which hardly feels vibration for the occupant is set, and if the torque Tet exceeding the second torque threshold Tth2 is generated, the operation control unit 33 performs three phase control from the totally open control. Switch to short circuit control. As a result, the relationship between the torque Tet of the motor 3 and the rotational speed becomes as shown in FIG. 3. Even if the downhill continues and the rotational speed of the motor 3 further increases, the torque Tet hardly fluctuates, and the vibration Can be suppressed.

  In FIG. 4, if the operation control unit 33 switches from the full release control to the three-phase short circuit control based on the rotational speed with the second rotational speed R2 of the motor 3 as a threshold, the second rotational speed detection error occurs. There is a case where switching is performed after exceeding the torque threshold Tth2. Therefore, in order to suppress the vibration of the electric vehicle so that the occupant hardly feels it, either one of the full opening control and the 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, the switching operation of the field weakening control in the normal control of the switching control unit 32 will be described with reference to FIG. 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 rotational speed of the motor 3. In this example, the switching control unit 32 calculates the rotational 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 the rotation speed of the motor 3 exceeds the high rotation threshold value. If the rotational speed of the motor 3 exceeds the high rotation threshold value, the process proceeds to step S12. If not, the process proceeds to step S13.

<Step S12>
When the rotational speed of the motor 3 exceeds the high rotation threshold value, the switching control unit 32 performs field weakening control on 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 21 u to 21 w and the magnetic pole position θe detected by the magnetic pole position sensor 22. The PWM control of the six gate signals respectively supplied to the six switching elements S1 to S6 is performed to control the switching operation of the inverter 11. By thus causing the negative d-axis current to flow, it is possible to reduce the magnetic flux in the d-axis direction by utilizing the demagnetization effect due to the armature reaction. As a result, the back electromotive force generated by the rotation of the motor 3 can be reduced, so that the rotational 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 cancels the field weakening control on the motor 3. For example, the switching control unit 32 performs PWM control on six gate signals respectively supplied to the six switching elements S1 to S6 so that other synchronous control such as maximum torque current control is performed on the motor 3. Thus, the switching operation of the inverter 11 is controlled.

[Abnormal action corresponding operation]
Next, with reference to FIG. 6, an abnormality occurrence handling operation of the operation control unit 33 will be described. The abnormality occurrence handling operation is performed when the abnormality determination unit 31 determines that there is an abnormality.

<Step S21>
First, the operation control unit 33 determines whether field weakening control on the motor 3 is being performed. For example, when the switching control unit 32 (specifically, the field weakening control unit 306) performs field weakening control on the motor 3, a flag (hereinafter referred to as "field weakening flag") indicating that field weakening control is being performed. 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 field weakening control is performed on the motor 3 based on the field weakening flag. If field weakening control is not performed on the motor 3 (for example, if the field weakening flag is turned off), the process proceeds to step S23. If not, the process proceeds to step S22.

<Step S22>
Next, the operation control unit 33 acquires the rotational speed of the motor 3. In this example, the operation control unit 33 calculates the rotational 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 the rotational speed of the motor 3 exceeds the rotational speed threshold. If the rotational speed of the motor 3 does not exceed the rotational speed threshold, the process proceeds to step S23. If not, the process proceeds to step S24. The rotational speed threshold may be, for example, a rotational speed at which the rate of increase of the absolute value of the torque Tet acting on the motor 3 does not increase based on FIG. 3, for example, the first rotational speed R1.

<Step S23>
When the field weakening control for the motor 3 is not performed or the field weakening control for the motor 3 is performed and the rotational speed of the motor 3 does not exceed the rotational speed threshold, the operation control unit 33 performs three-phase short circuit control The switching control unit 32 is controlled such that all open control is performed among all open controls. As a result, all of the three high side switching elements S1 to S3 and the 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 field weakening control is performed on motor 3 and the rotational speed of motor 3 exceeds the rotational speed threshold, operation control unit 33 performs three-phase short circuit control among three-phase short circuit control and full open control. Control the switching control unit 32. As a result, one of the high side switching element group including the three high side switching elements S1 to S3 and the low side switching element group including the three low side switching elements S4 to S6 is turned on and the other switching element is switched on. The element group is turned off, and the switching operation of the inverter 11 is stopped.

[Features of three-phase short circuit control and all open control]
When full open control is performed when it is determined by the abnormality determination unit 31 that there is an abnormality (for example, when an abnormality that the DC power supply 2 fails while the electric vehicle is traveling), the stator coil of the motor 3 is The stored power is supplied to the smoothing capacitor 12 via the freewheeling diode connected in anti-parallel to the switching elements S1 to S6 to charge the smoothing capacitor 12, and as a result, the voltage across the smoothing capacitor 12 rises. become. The increase in the voltage across the terminals of the smoothing capacitor 12 tends to increase as the rotational speed of the motor 3 increases. That is, when it is determined that abnormality is present by abnormality determination unit 31 and full open control is performed, the power line connecting DC power supply 2 and inverter 11 (power supply line LP and ground is connected as the rotational speed of motor 3 increases. The voltage applied to the line LG) increases, and the possibility of the power line connecting the DC power supply 2 and the inverter 11 becoming an overvoltage increases.

  On the other hand, when three-phase short circuit control is performed when it is determined by the abnormality determination unit 31 that there is an abnormality (for example, when an abnormality that the DC power supply 2 fails while the electric vehicle is traveling), three outputs Lines LOu to LOw are connected via small resistances (on resistances of switching elements S1 to S6), and as a result, three phase currents iu to iw flowing through three output lines LOu to LOw are instantaneous Will increase. The instantaneous increase of the phase currents iu to iw tends to increase as the rotational speed of the motor 3 decreases.

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

[Abnormal response operation]
Next, referring to FIG. 7, the abnormal continuation handling operation of the operation control unit 33 will be described. This abnormal continuation corresponding operation is repeatedly performed in a period (abnormality continuation period) after it is determined by the abnormality determination unit 31 that there is an abnormality.

<Step S25>
First, the operation control unit 33 determines whether three-phase short circuit control is performed in the switching control unit 32 or not. If three-phase short circuit control is performed in the switching control unit 32, the process proceeds to step S26. 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 the torque Tet acting on the motor 3 falls below the first torque threshold Tth1. If the torque Tet acting on the motor 3 falls below the first torque threshold Tth1, the process proceeds to step S27.

<Step S27>
When the torque Tet acting on the motor 3 falls below the first torque threshold Tth1 while the three-phase short circuit control is being performed, the operation control unit 33 terminates the three-phase short circuit control of the switching control unit 32 and performs all open control Control the switching control unit 32 to start.

<Step S28>
On the other hand, when the three-phase short circuit control is not performed in switching control unit 32 (that is, when the full opening control is performed in switching control unit 32), operation control unit 33 determines that the torque Tet acting on motor 3 is third. Whether or not 2 torque threshold Tth2 is exceeded it decides. If the torque Tet acting on the motor 3 exceeds the second torque threshold Tth2, the process proceeds to step S29.

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

[Effect by Embodiment 1]
As described above, the motor 3 is performed by performing either one of the three-phase short circuit control and the full open control according to the torque Tet acting on the motor 3 in the abnormal continuation period after it is determined that there is an abnormality by the abnormality determination. Both the rapid deceleration and the overvoltage of the power line connecting the DC power supply 2 and the inverter 11 can be effectively suppressed.

  In addition, the motor 3 is acquired (estimated) by obtaining the torque Tet acting on the motor 3 based on the phase currents iu to iw detected by the current sensors 21 u to 21 w and the magnetic pole position θe detected by the magnetic pole position sensor 22. There is no need to separately provide a torque sensor (not shown) for detecting the torque acting on the motor.

  Further, when it is determined that there is an abnormality by the abnormality determination, three-phase according to the operating state of the motor 3 (specifically, at least one of the presence or absence of execution of field weakening control on the motor 3 and the rotational speed of the motor 3). By performing either short circuit control or full open control, it is possible to appropriately perform control according to the operation state of the motor 3 among the three phase short circuit control and full open control.

  In addition, a rotational speed sensor (not shown) for detecting the rotational speed of the motor 3 is omitted by obtaining (calculating) the rotational speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. Can.

  Further, by performing abnormality determination on all of DC power supply 2, motor 3, inverter 11, and sensor 20, not only when abnormality occurs in DC power supply 2, DC power supply 2, motor 3 and inverter 11, and 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 operation state of the motor 3. Thus, it is possible to suppress not only the overvoltage of the power line (power supply line LP and ground line LG) due to the abnormality of DC power supply 2, but also the overvoltage of the power line due to abnormality of DC power supply 2, motor 3, inverter 11, and sensor 20.

(Modification of Embodiment 1)
Note that step S22 may be omitted in the abnormality occurrence handling operation of 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 either one of the three-phase short circuit control and the all-open control according to whether or not field weakening control is performed on the motor 3. You may be comprised so that the control part 32 may perform. Specifically, when the field weakening control on the motor 3 is performed, the operation control unit 33 causes the switching control unit 32 to perform the three-phase short circuit control, and the field weakening control on the motor 3 is not performed. The switching control unit 32 may be configured to perform the full release control.

  Further, step S21 may be omitted in the abnormality occurrence handling operation of 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 one of the three-phase short circuit control and the all open control to the switching control unit 32 according to the rotational speed of the motor 3. It may be configured to be performed. Specifically, when the rotational speed of the motor 3 exceeds the predetermined rotational speed threshold, the operation control unit 33 causes the switching control unit 32 to perform three-phase short circuit control, and the rotational speed of the motor 3 is the rotational speed If the threshold value is not exceeded, the switching control unit 32 may be configured to perform the full release control.

Second Embodiment
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 is different from the motor control device 10 according to the first embodiment in the configuration of the control unit 30. The other configuration of the motor control device 10 according to the second embodiment is the same as the configuration 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 determines that there is an abnormality in the abnormality determination. Output to 33. The operation control unit 33 causes the switching control unit 32 to perform normal control until the abnormality determination unit 31 outputs the abnormality detection signal S31. In addition, when the abnormality detection unit 31 outputs the abnormality detection signal S31, the operation control unit 33 performs either one of the three-phase short circuit control and the all open control to the switching control unit 32 according to the operation state of the motor 3. Let Then, in the operation control unit 33, the operation control unit 33 performs a three-phase short circuit according to the torque Tet acting on the motor 3 in a period (abnormality continuation period) after the abnormality determination unit 31 outputs the abnormality detection signal S31. The switching control unit 32 performs one of control and full release control.

  Note that the normal operation (operation performed until abnormality detection signal S31 is output), the abnormality occurrence response operation (operation performed when abnormality detection signal S31 is output), and abnormality continuation in operation control unit 33 in the second embodiment The corresponding operation (the operation performed in the period after the abnormality detection signal S31 is output) is the same as the normal operation, the abnormality occurrence correspondence operation, and the abnormality continuation correspondence 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 any one of normal control, three-phase short circuit control, and all open control Control signal S 33 for causing the switching control unit 32 to output a signal. The switching control unit 32 performs any one of normal control, three-phase short circuit control and full open control in response to the control signal S33 output from 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 the switching elements S1 to S6. And a drive circuit such as a gate drive IC that supplies on / off signals to control 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 by Embodiment 2]
As described above, by configuring the abnormality determination unit 31 by hardware, it is possible to perform abnormality determination in the abnormality determination unit 31 more quickly than when configuring the abnormality determination unit 31 by software.

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

  As described above, in the description of the first and second embodiments, it is assumed that the control unit 30 (the switching control unit 32 and the operation control unit 33) acquires the rotational speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. Although mentioned as an example, the motor control device 10 may be provided with a rotational speed sensor (not shown) that detects the rotational speed of the motor 3. Then, the control unit 30 (the switching control unit 32 and the operation control unit 33) may be configured to obtain the rotational speed of the motor 3 by inputting the rotational speed detected by the rotational speed sensor.

  In 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 where the torque Tet acting on the motor 3 is acquired 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.

  In addition, Embodiments 1 and 2 and the modification may be combined as appropriate. The above embodiments and modifications are essentially preferred exemplifications, and are not intended to limit the scope of the present invention, the applications thereof, or the applications thereof.

(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. The other configuration of the motor control device 40 according to the third embodiment is the same as the configuration 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 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 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 by supplying gate signals to the switching elements S1 to S6. It is comprised by drive circuits, such as gate drive IC which controls on-off of element S1-S6.

  In this example, the control unit 50 includes the phase currents iu to iw detected by the current sensors 21 u to 21 w, 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 the electric vehicle) is input.

  Further, in this example, the control unit 50 includes 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 configure 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 performs abnormality determination on 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 controls the operation of the inverter 11 based on the information detected by the sensor 20 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. Control switching operation. Specifically, the normal control unit 52 detects signals from various sensors such as the current sensors 21 u to 21 w 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 (specifically 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 field weakening control on the motor 3 according to the rotational 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 in FIG. Is configured.

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

  In this example, the abnormality control unit 53 determines whether or not the field weakening control is performed on the motor 3 by the normal control unit 52 and the motor 3 in the same manner as the abnormality occurrence handling operation by the control unit 30 of the first embodiment described in FIG. According to at least one of the rotational speeds, one of the three-phase short circuit control and the all open control is selected and performed.

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

<Step S31>
First, the abnormality control unit 53 determines 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>
If 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 determines that the high side switching element group including the three high side switching elements S1 to S3 and the three low sides Of the low-side switching element group consisting of the switching elements S4 to S6, the switching element group including the switching elements determined to be short circuit abnormality by the abnormality determining unit 51 is turned on. For example, when the abnormality determination unit 51 determines that the first high side switching element S1 is in the short circuit abnormality, the abnormality control unit 53 turns on the three high side switching elements S1 to S3 and turns on the three low side switching The gate signals supplied to the six switching elements S1 to S6 are controlled such 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 six switching elements (based on the result of the abnormality determination by the abnormality determining unit 51 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 have an open abnormality among the six switching elements S1 to S6, the process proceeds to step S34. 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 determines that the high side switching element group including the three high side switching elements S1 to S3 and the three low sides Of the low-side switching element group consisting of the switching elements S4 to S6, the switching element group including the switching elements determined to be open abnormality by the abnormality determining unit 51 is turned off. For example, when the abnormality determination unit 51 determines that the first high side switching element S1 is in the open abnormality, the abnormality control unit 53 turns off the three high side switching elements S1 to S3 and three low side switchings. The gate signals supplied to the six switching elements S1 to S6 are controlled such that the elements S4 to S6 are turned on.

<Step S35>
If there is no switching element determined to be short circuit abnormality among the six switching elements S1 to S6 and no switching element determined to be open abnormality, the abnormality control unit 53 selects the three high side switching elements S1. A predetermined switching element group among the low side switching element group consisting of the high side switching element group consisting of ~ S3 and the three low side switching elements S4 to S6 is turned on. For example, when there are no switching elements determined to be short circuit abnormal among the six switching elements S1 to S6 and no switching elements determined to be open abnormality, switching to be turned on in three-phase short circuit control When the low side switching element group is predetermined as the element group, the abnormality control unit 53 causes the three high side switching elements S1 to S3 to be turned off and the three low side switching elements S4 to S6 to be turned on. Control the gate signals supplied to the six switching elements S1 to S6.

[Effect by 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 in the case where an abnormality occurs in the DC power supply 2, When an abnormality occurs in at least one of the motor 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 operation state of the motor 3. Thus, it is possible to suppress not only the overvoltage of the power line (power supply line LP and ground line LG) due to the abnormality of DC power supply 2, but also the overvoltage of the power line due to abnormality of DC power supply 2, motor 3, inverter 11, and sensor 20.

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

  In the three-phase short circuit control, it is determined that the abnormality determination unit 51 is an open abnormality in the high side switching element group including three high side switching elements S1 to S3 and the low side switching element group including three low side switching elements S4 to S6. An open abnormality has occurred in six switching elements (three high-side switching elements S1 to S3 and three low-side switching elements S4 to S6) by turning off the switching element group including the determined switching elements. Even in the case, three-phase short circuit control can be performed normally.

  In addition, DC power supply 2 is selected by selecting one of three-phase short circuit control and full open control according to at least one of the presence or absence of field weakening control to motor 3 by normal control unit 52 and the rotational speed of motor 3. When an abnormality occurs in at least one of the motor 3, the inverter 11, and the sensor 20, it is possible to appropriately perform the control according to the operation state of the motor 3 among the three-phase short circuit control and the full open control.

  In addition, a rotational speed sensor (not shown) for detecting the rotational speed of the motor 3 is omitted by obtaining (calculating) the rotational speed of the motor 3 based on the magnetic pole position θe detected by the magnetic pole position sensor 22. Can.

(Modification of Embodiment 3)
Note that step S22 may be omitted in the operation of the abnormality control unit 53 shown in FIG. That is, the abnormality control unit 53 may be configured to select one of the three-phase short circuit control and the full release control according to whether or not the field weakening control on the motor 3 by the normal control unit 52 is performed. Specifically, when the field weakening control on the motor 3 is performed by the normal control unit 52, the abnormality control unit 53 selects the three-phase short circuit control, and the field weakening control on the motor 3 is performed by the normal control unit 52. It may be configured to select all release control when there is not.

  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 one of the three-phase short circuit control and the full release control in accordance with the rotational speed of the motor 3. Specifically, the abnormality control unit 53 selects three-phase short circuit control when the rotational speed of the motor 3 exceeds a predetermined rotational speed threshold, and the rotational speed of the motor 3 does not exceed the rotational speed threshold. It may be configured to select full release 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 is different from the motor control device 40 according to the third embodiment in the configuration of the control unit 50. The other configuration of the motor control device 40 according to the second embodiment is the same as the configuration of the motor control device 40 according to the third embodiment.

  As shown in FIG. 11, the control unit 50 of the fourth embodiment is different from the control unit 50 of the third embodiment in the configuration of the abnormality control unit 53. The other configuration of the control unit 50 of the fourth embodiment is the same as the configuration of the control unit 50 of the third embodiment.

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

<Error control selector>
The abnormality control selection unit 531 is a three-phase short circuit according to the operation 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 release control.

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

  In this example, the abnormality control selector 531 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 as in the normal controller 52. Specifically, the abnormality control selector 531 calculates the rotational speed of the motor 3 by differentiating the magnetic pole position θe detected by the magnetic pole position sensor 22.

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

  Further, in this example, in the three-phase short circuit control, the abnormality control execution unit 532 includes a high side switching element group including three high side switching elements S1 to S3 and a low side switching element group including three low side switching elements S4 to S6. Among them, the switching element group including the switching elements determined to be short-circuiting abnormal by the abnormality judging unit 31 is configured to be turned on.

  Further, in this example, in the three-phase short circuit control, the abnormality control execution unit 532 includes a high side switching element group including three high side switching elements S1 to S3 and a low side switching element group including three low side switching elements S4 to S6. Among them, the switching element group including the switching elements determined to be the open abnormality by the abnormality determining unit 31 is configured to be turned off.

[Operation by Abnormal Control Selection Unit]
Next, with reference to FIG. 12, the operation of the abnormality control selection unit 531 will be described. The operation of the abnormality control selection unit 531 is repeated until it is determined by the abnormality determination unit 51 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 on the motor 3 by the normal control unit 52 is being performed. If the field weakening control on the motor 3 is not performed, the process proceeds to step S43. If not, the process proceeds to step S42.

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

<Step S43>
When the field weakening control on the motor 3 is not performed by the normal control unit 52, or the field weakening control on the motor 3 is performed and the rotation speed of the motor 3 does not exceed the rotation speed threshold, the abnormality control selection unit 531 Of the three-phase short circuit control and the all open control, the all open control is selected. For example, the abnormality control selection unit 531 brings down a flag (hereinafter referred to as a “processing flag”) for identifying which of the three-phase short circuit control and the all open control is selected. That is, when the processing flag is set, the three-phase short circuit control is selected among the three phase short circuit control and the all open control, and when the process flag is turned off, the three phase short circuit control All open control is selected among all open control.

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

[Operation by Abnormal Control Execution Unit]
Next, with reference to FIG. 13, the operation of the abnormality control execution unit 532 will be described. 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 the three-phase short circuit control is selected among the three-phase short circuit control and the all open control by the abnormality control selection unit 531 (for example, whether the process flag is set). . If three-phase short circuit control is selected by the abnormality control selection unit 531 (if the processing flag is set), the process proceeds to step S52. If not, the process proceeds to step S53.

<Step S52>
When three-phase short circuit control is selected by the abnormality control selection unit 531, the abnormality control execution unit 532 performs three-phase short circuit control among the three-phase short circuit control and the all open control. As a result, one of the high side switching element group including the three high side switching elements S1 to S3 and the low side switching element group including the three low side switching elements S4 to S6 is turned on and the other switching element is switched on. 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 three-phase short circuit control is not selected by abnormality control selection unit 531 (that is, all open control is selected), abnormality control execution unit 532 is fully open among three phase short circuit control and all open control. Take control. As a result, all of the three high side switching elements S1 to S3 and the three low side switching elements S4 to S6 are turned off, and the switching operation of the inverter 11 is stopped.

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

(Modification 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 one of the three-phase short circuit control and the full release control according to whether or not the field weakening control on the motor 3 by the normal control unit 52 is performed. . Specifically, when the field weakening control on the motor 3 is performed by the normal control unit 52, the abnormality control selection unit 531 selects three-phase short circuit control, and the field weakening control on the motor 3 is performed by the normal control unit 52. If not, it may be configured to select the full release control.

  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 one of the three-phase short circuit control and the full release control in accordance with the rotational speed of the motor 3. Specifically, the abnormality control selection unit 531 selects three-phase short circuit control when the rotational speed of the motor 3 exceeds a predetermined rotational speed threshold, and the rotational speed of the motor 3 does not exceed the rotational speed threshold. May be configured to select the full release 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 differs from the motor control device 40 according to the third embodiment in the configuration of the control unit 50. The other configuration of the motor control device 40 according to the fifth embodiment is the same as the configuration 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 configured by hardware that is 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 the switching elements S1 to S6. It is comprised by drive circuits, such as gate drive IC which controls on-off of switching element S1-S6. That is, in this example, the normal control unit 52 and the abnormality control unit 53 are realized by software, and constitute a part of the function 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.

  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 determination unit 51 outputs the abnormality detection signal S51. ing. The operation by the normal control unit 52 of the fifth embodiment (the operation performed until the abnormality detection unit 51 outputs the abnormality detection signal S51) is the operation by the normal control unit 52 of the third embodiment (an abnormality is detected by the abnormality determination unit 51). Is the same as the operation performed until it is determined.

  Then, in the fifth embodiment, when the abnormality detection unit 51 outputs the abnormality detection signal S5, the abnormality control unit 53 selects one of the three-phase short circuit control and the all open control according to the operation state of the motor. Is configured to perform. The operation by the abnormality control unit 53 of the fifth embodiment (the operation performed after the abnormality detection unit 51 outputs the abnormality detection signal S51) is the operation by the abnormality control unit 53 of the first embodiment (an abnormality is detected by the abnormality determination unit 51). Is the same as the operation performed after it is determined.

  The other configuration of the control unit 50 of the fifth embodiment is the same as the configuration 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, it is possible to perform abnormality determination in the abnormality determination unit 51 more quickly than when configuring the abnormality determination unit 51 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 configured by 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. When 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 determination unit 51 outputs the abnormality detection signal S51. Then, when the abnormality detection unit 51 outputs the abnormality detection signal S51, the abnormality control unit 53 is configured to select one of the three-phase short circuit control and the all open control according to the operation state of the motor. It may be done.

  Specifically, before the abnormality detection unit 51 outputs the abnormality detection signal S51, the abnormality control selection unit 531 selects one of the three-phase short circuit control and the all open control according to the operation state of the motor 3. If the abnormality detection unit 51 outputs the abnormality detection signal S51, the abnormality control execution unit 532 selects one of the three-phase short circuit control and the all open control by the abnormality control selection unit 531. It may be configured to perform the controlled control.

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

  The third, fourth, and fifth embodiments may be implemented in combination with the modification as appropriate, and the first, second and third modification may be implemented in combination as appropriate.

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

  The above embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, the applications thereof, or the applications thereof.

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

10, 40 Motor control unit 2 DC power supply 3 Motor 11 Inverter 12 Smoothing capacitor 20 Sensor 21u-21w Current sensor 22 Magnetic pole position sensor 30, 50 Control unit 31, 51 Abnormality judgment 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 (15)

A motor control device for controlling a three-phase AC motor by the power of a DC power supply, comprising:
Three high-side switching elements respectively connected between three output lines respectively connected to three input terminals of the motor and a power supply line connected to a positive electrode of the DC power supply;
An inverter having three low side switching elements respectively connected between the three output lines and a ground line connected to the negative electrode of the DC power supply;
A sensor that detects information used to control the switching operation of the inverter;
And a control unit,
The control unit
Performing abnormality determination on at least one of the DC power supply, the motor, the inverter, and the sensor;
The normal control is performed to control 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.
From the high side switching element group consisting of the three high side switching elements and the three low side switching elements according to the torque acting on the motor in the abnormal continuation period after it is determined that there is an abnormality by the abnormality determination Three-phase short circuit control for turning on one switching element group and turning off the other switching element group among the low side switching element groups, and turning off all of the high side switching element group and the low side switching element group Do either one of all open control to
Motor controller. The control unit
An abnormality determination unit that performs abnormality determination on 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 full open control, and the normal control is performed by the switching control unit until the abnormality determination unit determines that there is an abnormality. The operation control unit causes the switching control unit to perform either one of the three-phase short circuit control and the all-open control according to the torque acting on the motor in a period.
The motor control device according to claim 1. The abnormality determination unit is configured by 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. Outputting an abnormality detection signal 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 the control signal for performing any one of the normal control, the three-phase short circuit control, and the all open control is switched. Output to the control unit
A motor control device according to claim 2 or 3. 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 in the abnormal duration period. The full open control is started, and the full open control is ended when the torque acting on the motor exceeds a predetermined second torque threshold when the full open control is being performed, 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 in the motor, and a magnetic pole position sensor that detects a magnetic pole position of the motor,
The control unit acquires a 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,
If it is determined by the abnormality determination that there is an abnormality, either one of the three phase short circuit control and the all open control is performed according to at least one of the presence or absence of the field weakening control for the motor and the rotational speed of the motor. Do,
The motor control apparatus of any one of Claims 1-6. The control unit
An abnormality determination unit that performs abnormality determination on the DC power supply, the motor, the inverter, and the sensor;
Usually, the switching operation of the inverter is controlled based on the information detected by the sensor until the abnormality determination unit determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. A control unit,
And an abnormality control unit,
The abnormality control unit
Before the abnormality determination unit determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal, the three-phase short circuit control and the full open control according to the operation state of the motor An abnormal control selection unit that selects one of
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 one of the three-phase short circuit control and the all open control. And an abnormal control execution unit for performing the controlled control,
The motor control device according to claim 1. The abnormality determination unit is configured by hardware separate from the normal control unit and the abnormality control unit, and an abnormality is determined when it is determined that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. Output detection signal,
The normal control unit controls the switching operation of the inverter based on the information detected by the sensor until the abnormality detection unit outputs the abnormality detection signal.
When the abnormality detection unit outputs the abnormality detection signal, the abnormality control unit selects one of the three-phase short circuit control and the all-open control according to the operation state of the motor.
The motor control device according to claim 8. The abnormality determination unit determines whether or not there is a short circuit abnormality in which the switching element is always in the ON state for each of the three high side switching elements and the three low side switching elements.
The abnormality control unit turns on, in the three-phase short circuit control, a switching element group including a 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. Configured to be in state,
The motor control device according to claim 8. The abnormality determination unit is configured to determine whether or not there is an open abnormality in which the switching element is always in an off state with respect to each of the three high side switching elements and the three low side switching elements.
The abnormality control unit turns off, in the three-phase short circuit control, a switching element group including a switching element determined to be the open abnormality by the abnormality determination unit among the high side switching element group and the low side switching element group. Configured to be in state,
The motor control device according to claim 8. A motor control device for controlling a three-phase AC motor by the power of a DC power supply, comprising:
Three high-side switching elements respectively connected between three output lines respectively connected to three input terminals of the motor and a power supply line connected to a positive electrode of the DC power supply; An inverter having three low side switching elements respectively connected between the ground line connected to the negative electrode of the DC power supply;
A sensor that detects information used to control the switching operation of the inverter;
An abnormality determination unit that performs abnormality determination on the DC power supply, the motor, the inverter, and the sensor;
Usually, the switching operation of the inverter is controlled based on the information detected by the sensor until the abnormality determination unit determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. A control 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 determination unit, a high state including the three high side switching elements according to the operation state of the motor Three-phase short circuit control for turning on one switching element group and turning off the other switching element group among the low-side switching element group including the side switching element group and the three low-side switching elements, and the high-side switching element And an abnormality control unit which selects and performs any one of full opening control for turning off all of the group and the low side switching element group,
The abnormality control unit
Before the abnormality determination unit determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal, the three-phase short circuit control and the full open control according to the operation state of the motor An abnormal control selection unit that selects one of
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 one of the three-phase short circuit control and the all open control. And an abnormal control execution unit for performing the controlled control,
Motor controller. Three high-side switching elements respectively connected between three output lines respectively connected to three input terminals of a three-phase AC motor and a power supply line connected to the positive electrode of the DC power supply; An inverter having three low-side switching elements respectively 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 to control the switching operation of the inverter A control method of the provided motor control device,
An abnormality determination step of performing abnormality determination on at least one of the DC power supply, the motor, the inverter, and the sensor;
A normal control step of controlling the switching operation of the inverter based on the information detected by the sensor until the abnormality determination step determines that there is an abnormality;
The high-side switching element group including the three high-side switching elements and the three low-side switching elements according to the torque acting on the motor in an abnormal continuation period after it is determined that there is an abnormality in the abnormality determination step Three-phase short circuit control in which one switching element group is turned on and the other switching element group is turned off in the low-side switching element group consisting of two, and the high side switching element group and all the low side switching element groups are turned off And an abnormal continuation corresponding step of performing any one of all release control to be in the state;
Control method of motor control device. Further includes an abnormality control step,
The abnormality control step is
The three-phase short circuit control and the full open control according to the operation state of the motor before the abnormality determination step determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. An abnormal control selection step of selecting one of
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 abnormality control selection step of the three-phase short circuit control and the all open control is performed. An abnormal control execution step of performing selected control;
The control method of the motor control apparatus of Claim 13. Three high-side switching elements respectively connected between three output lines respectively connected to three input terminals of a three-phase AC motor and a power supply line connected to the positive electrode of the DC power supply; An inverter having three low-side switching elements respectively 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 to control the switching operation of the inverter A control method of the provided motor control device,
An abnormality determination step of performing abnormality determination on 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 high-side switching element includes the three high-side switching elements according to the operation state of the motor Three-phase short-circuit control for turning on one switching element group of the high-side switching element group and the low-side switching element group consisting of the three low-side switching elements and turning off the other switching element group An abnormality control step of selecting either one of an element group and a full open control for turning off all the low side switching element groups;
The abnormality control step is
The three-phase short circuit control and the full open control according to the operation state of the motor before the abnormality determination step determines that at least one of the DC power supply, the motor, the inverter, and the sensor is abnormal. An abnormal control selection step of selecting any one of the three-phase short circuit 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 determination step; And an abnormal control execution step of performing control selected by the abnormal control selection step among the full release control,
Control method of motor control device.

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