JP5261107B2 - Motor drive device, motor drive system, and electric vehicle - Google Patents

Description

  The present invention relates to a motor driving device and a motor driving system for driving a motor. The present invention also relates to an electric vehicle that travels by a motor drive system.

  A conventional motor driving apparatus for driving a motor is disclosed in Patent Document 1. This motor drive device includes a motor controller, a control circuit, and alternative signal means. The motor controller outputs a command value for driving the motor to the control circuit. The command value is composed of digital signals such as current, voltage, and speed for driving the motor, and is transmitted to the control circuit by serial communication. The control circuit monitors the rotation state of the motor and energizes the motor so as to conform to the command value received from the motor controller.

  When communication between the motor controller and the control circuit is interrupted due to a failure, disconnection of a signal line, or the like, a predetermined substitute signal is sent to the control circuit by the substitute signal means. The control circuit energizes the motor based on the substitute signal. Thereby, even if the command value is interrupted, it is possible to avoid a non-control state in which the motor continues to rotate without changing the command value before the disruption.

Japanese Patent Laid-Open No. 2002-17095 (page 3 to page 4, FIG. 1)

  However, according to the above-described conventional motor driving apparatus, the state in which the motor controller transmits the command value to the control circuit due to a bug in the control software is maintained, and a constant command value may continue to be output. At this time, since a command value is sent from the motor controller to the control circuit, there is a problem that the motor cannot be switched to and the motor continues to rotate. In particular, in the case of an electric vehicle in which wheels are driven by a motor drive system and a motor drive system including a motor, the danger continues to increase at the same speed.

  An object of this invention is to provide the motor drive device which can prevent the malfunction which a motor continues rotating, a motor drive system using the same, and an electric vehicle.

  In order to achieve the above object, the present invention provides a motor drive device comprising: a motor controller that outputs a command value for driving a motor; and a motor drive module that drives the motor based on the command value. The drive module has a command value change detection unit that detects whether or not the command value has been changed, and a command value correction unit that corrects the command value, and the command value has not been changed within a predetermined period. In addition, a correction command value obtained by correcting the command value in a direction in which the motor decelerates is derived by the command value correction unit, and the motor is driven by the correction command value.

  According to this configuration, a command value such as torque is sent from the motor controller to the motor drive module. In the motor drive module, the command value change detection unit monitors the output of the motor controller to determine whether or not the command value has been changed. When the command value is not changed within the predetermined period, a corrected command value is derived by correcting the command value in the direction in which the motor decelerates by the command value correction unit. For example, when the command value is composed of torque, a correction command value that is smaller than the command value is derived. Then, the motor is driven based on the correction command value output from the command value correction unit. When the command value is changed within a predetermined period, the command value is output from the command value correction unit, or the correction command value close to the command value is output.

  According to the present invention, in the motor drive device having the above-described configuration, the command value correction unit monitors the detection result of the command value change detection means for each control period, and the command value correction unit continuously detects the detection result. When the command value is not changed, the correction command value is gradually changed to a value for stopping the motor.

  According to this configuration, when there is no change in the command value within a predetermined period, a correction command value corrected in the direction of decelerating the motor is output, and when there is no change in the command value within the subsequent control cycle, the previous correction command is output. A correction command value in which the value is further corrected in the direction of decelerating the motor is output. This operation is repeated during a period in which the command value is not changed, and the motor stops when it is repeated a predetermined number of times.

  According to the present invention, in the motor drive device having the above-described configuration, when the command value is changed within the next control cycle in which the motor is driven with the correction command value, the motor drive state based on the previous correction command value is used. The motor is driven by the corrected command value obtained by correcting the command value in a direction approaching the motor driving state by the command value.

  According to this configuration, when there is no change in the command value within a predetermined period, a corrected command value corrected in the direction of decelerating the motor is output. If the command value is changed within the subsequent control cycle, the correction command value is varied so as to approach the motor drive state of the input command value with respect to the motor drive state of the previous correction command value. Then, the variable correction command value is output to drive the motor. For example, when the command value composed of torque is changed and larger than the previous correction command value, the correction command value is increased.

  According to the present invention, in the motor drive device having the above-described configuration, the motor controller outputs the command value by changing the minimum digit of the command value when the command value is the same as the command value output last time.

  According to this configuration, for example, a digital signal of a command value such as torque is output from the motor controller. For the command value, the least significant bit, which is the smallest digit, is switched between 0 and 1 for each output, and a command value different from the previous one is output. Further, when the command value is the same as the previous time, for example, 1 is added to or subtracted from the least significant bit which is the minimum digit, and a command value different from the previous value is output. Since the minimum digit of the command value is within the error range, the motor operation is not affected, and the command value change detection unit detects that the command value output from the motor controller has been changed from the previous time. The motor controller may change and output the minimum digit of the previous command value when the command value is the same for a predetermined number of times.

  A motor drive system according to the present invention includes the motor drive device having the above-described configuration and a motor driven by the motor drive device.

  The electric vehicle of the present invention includes the motor drive system configured as described above, a main controller that transmits a throttle opening to the motor controller, and a wheel that is rotated by the motor, and the electric vehicle according to the throttle opening. The wheel is driven by outputting a command value by the motor controller.

  According to this configuration, the throttle opening is output from the main controller to the motor controller, and the motor controller outputs a command value corresponding to the throttle opening. The motor drive module drives the motor based on the correction command value output from the command value correction unit.

  According to the present invention, the motor can be decelerated when the command value is interrupted or when a constant command value is continuously transmitted due to a bug in the motor controller or the like. Therefore, it is possible to prevent a problem that the motor driving device, the motor driving system including the motor driving device, and the motor of the electric vehicle continue to rotate.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of an electric vehicle according to an embodiment. The electric vehicle 1 has a main controller 2 that controls each part. A key 5, a throttle 6, an electrical system 7, a battery controller 3, and a motor drive system 20 are connected to the main controller 2.

  The key 5 is operated by the user to activate the main controller 2. The throttle 6 is opened and closed by the user, and instructs to increase or decrease the speed of the electric vehicle 1 according to the opening degree. The electrical system 7 includes various electric transmission devices provided in the electric vehicle 1. The battery 4 supplies power to each part of the electric vehicle 1. The battery controller 3 is connected to the battery 4 and controls charging / discharging of the battery 4.

  The motor drive system 20 includes a motor drive device 10 having a motor controller 11 and a motor drive module 12, and a motor 18 that rotates wheels (not shown). The main controller 2, the battery controller 3, the motor controller 11, and the motor drive module 12 are connected by a communication line 8, and can be communicated by a LAN such as CAN.

  Information on the opening degree of the throttle 6 is transmitted from the main controller 2 to the motor controller 11, and information on the rotational speed of the motor 18 is transmitted from the motor drive module 12. The motor controller 11 derives a command value D0 such as torque and rotational speed for driving the motor 18 based on the opening degree of the throttle 6 and the rotational speed of the motor 18, and transmits it to the motor drive module 12.

  Note that the motor controller 11 and the main controller 2 may be configured integrally, or the motor controller 11 and the motor drive module 12 may be configured integrally. At this time, the communication line 8 between them is omitted, and each piece of information is transferred without going through a LAN or the like.

  FIG. 2 is a block diagram showing details of the motor drive module 12. The motor drive module 12 includes a command value change detection unit 13, a command value correction unit 14, a timer 15, a vector control unit 16, and an inverter 17. The command value change detection unit 13 receives the command value D0 output from the motor controller 11, and detects whether or not the command value D0 has changed. The command value change detection unit 13 determines that the command value D0 is not changed when the command value D0 is interrupted.

  The command value correction unit 14 receives a command value D0 from the motor controller 11. Further, the command value correction unit 14 receives information as to whether or not the command value D0 has been changed from the command value change detection unit 13 in a predetermined control cycle detected by the timer 15. Then, the command value correcting unit 14 outputs a corrected command value D1 obtained by correcting the command value D0 based on whether the command value D0 and the command value D0 are changed.

  The vector control unit 16 receives the correction command value D1 from the command value correction unit 14, and controls the output of the inverter 17 so that the current flowing through the motor 18 becomes the current value indicated by the correction command value D1. The inverter 17 is operated by the vector control unit 16, converts a direct current from the battery 4 into an alternating current, and supplies the alternating current to the motor 18.

  FIG. 3 is a flowchart showing the operation of the motor controller 11. In step # 11, a flag F1 indicating the least significant bit of the command value D0 is initialized and 0 is substituted. In step # 12, a torque command value D0 is calculated based on the opening degree of the throttle 6 and the rotational speed of the motor 18. In step # 13, it is determined whether or not the flag F1 is zero. If the flag F1 is 0, the process proceeds to step # 14. If the flag F1 is 1, the process proceeds to step # 16.

  In step # 14, the least significant bit of the command value D0 calculated in step # 12 is set to zero. In step # 15, 1 is assigned to the flag F1. In step # 16, the least significant bit of the command value D0 calculated in step # 12 is set to 1. In step # 17, 0 is assigned to the flag F1.

  In step # 18, the command value D0 is transmitted to the command value change detection unit 13 and the command value correction unit 14, and steps # 12 to # 18 are repeatedly performed.

  Thereby, even if the command value D0 calculated in step # 12 is the same value, the command value D0 in which the least significant bit that is the minimum digit is different from the previous value is transmitted. It may be determined whether or not the command value D0 calculated in step # 12 is the same as the previous value, and when the value is the same, 1 may be added to or subtracted from the minimum digit and a command value D0 different from the previous value may be transmitted.

  FIG. 4 is a flowchart showing the operation of the command value change detection unit 13. In step # 21, it is determined whether or not the command value D0 has been received. If the command value D0 has not been received, the process proceeds to step # 25 described later. If the command value D0 is received, it is determined in step # 22 whether or not it is different from the command value D0 received last time. If it is different from the previously received command value D0, 1 is assigned to a flag F2 indicating whether or not the command value D0 has been changed in step # 23. In step # 24, the command value D0 received and changed this time is stored in the memory.

  If it is the same as the previously received command value D0, the process proceeds to step # 25. In step # 25, 0 is assigned to the flag F2. Since the command value D0 is not changed, it is not necessary to store it again in the memory. In step # 26, the flag F2 is transmitted to the command value correction unit 14, and steps # 21 to # 26 are repeatedly performed.

  As a result, when the same command value D0 is continuously transmitted due to a bug in the control software of the motor controller 11 or when communication is interrupted, the command value correction unit indicates that the command value D0 is not changed by the flag F2 (= 0). 14 is transmitted.

  FIG. 5 is a flowchart showing the operation of the command value correction unit 14. In step # 31, a counter i indicating the number of control cycles is initialized and 10 is substituted. In step # 32, the initial value 0 is substituted for the correction command value D1. In step # 33, it is determined whether or not the control period has elapsed by detection of the timer 15.

  When the control cycle elapses, the command value D0 and the flag F2 are acquired in step # 34. At this time, the flag F2 and the command value D0 are synchronously transmitted from the motor controller 11 and the command value change detection unit 13 through the above-described steps # 18 and # 26. In step # 35, it is determined whether or not the flag F2 is 1. When the flag F2 is 0 (when the command value D0 is not changed), the process proceeds to step # 51. When the flag F2 is 1 (when the command value D0 is changed), the process proceeds to step # 36.

  Since the command value D0 is changed when the motor drive system 20 is activated, the process proceeds to step # 36. In step # 36, the counter i is initialized and 10 is substituted. Then, steps # 41 to # 46 described later are performed.

  If there is no change in the command value D0 as determined in step # 35 (flag F2 = 0), the process proceeds to step # 51 and the counter i is decremented. In step # 52, it is determined whether or not the counter i has become 0 or less. If the counter i is greater than 0, the process proceeds to step # 41.

  If the counter i becomes equal to or smaller than 0 in step # 52, the correction command value D1 is subtracted by a predetermined value δ2 in step # 53. As a result, the correction command value D1 representing the torque is reduced and corrected so that the motor 18 decelerates. In step # 54, it is determined whether or not the correction command value D1 has become smaller than 0 by subtraction.

  When the correction command value D1 is 0 or more, the process proceeds to step # 61. If the correction command value D1 is smaller than 0, 0 is substituted for the correction command value D1 in step # 55, and the process proceeds to step # 61. In step # 61, the correction command value D1 is stored in the memory. In step # 62, the correction command value D1 is transmitted to the vector control unit 16, and the process returns to step # 33.

  As a result, if there is no change in the command value D0 within a predetermined period of 10 control cycles, a corrected command value D1 is output in which the command value D0 is corrected in the direction in which the motor 18 decelerates. While the command value D0 is not changed, the counter i is negative, and the correction command value D1 is further decreased by a predetermined value δ2 every control cycle. Thus, the correction command value D1 is gradually changed until the motor 18 is stopped at each control cycle.

  If the command value D0 is changed while the correction command value D1 is subtracted in steps # 51 to # 55, the process proceeds to step # 36 based on the determination in step # 35. In step # 36, the counter i is initialized and 10 is substituted, and the process proceeds to step # 41.

  In step # 41, it is determined whether or not the previous correction command value D1 is equal to or less than the newly acquired command value D0. If the previous correction command value D1 is less than or equal to the command value D0, the correction command value D1 is added by a predetermined value δ1 in step # 42. As a result, the correction command value D1 is changed to a value close to the command value D0.

  In step # 43, it is determined whether or not the correction command value D1 to which the predetermined value δ1 has been added is greater than the command value D0. If the correction command value D1 is less than or equal to the command value D0, the process proceeds to step # 61. If the correction command value D1 is larger than the command value D0, the command value D0 is substituted for the correction command value D1 in step # 44, and the process proceeds to step # 61.

  If the previous correction command value D1 is larger than the command value D0, the correction command value D1 is subtracted by a predetermined value δ1 in step # 45. As a result, the correction command value D1 is changed to a value close to the command value D0. In step # 46, it is determined whether or not the correction command value D1 obtained by subtracting the predetermined value δ1 is smaller than the command value D0. If the correction command value D1 is greater than or equal to the command value D0, the process proceeds to step # 61. When the correction command value D1 becomes smaller than the command value D0, the command value D0 is substituted for the correction command value D1 in step # 44, and the process proceeds to step # 61.

  When the command value D0 is changed in steps # 41 to # 46, the correction command value D1 is varied so as to approach the command value D0 by a predetermined value δ1. Therefore, sudden torque fluctuations of the motor 18 can be prevented, and the safety of the motor drive system 20 and the electric vehicle 1 can be improved. Further, when the motor drive system 20 is activated, the correction command value D1 is varied so as to approach 0 from the command value D0.

  According to the present embodiment, when the command value D0 is not changed within a predetermined period (10 control cycles), the command value D0 is corrected by the command value correction unit 14 in the direction in which the motor 18 decelerates. Since the motor 18 is driven, the motor 18 can be decelerated when a constant command value D0 continues to be transmitted due to a bug in the control software of the motor controller 11 or the like. Similarly, the motor 18 can be decelerated when communication of the command value D0 is interrupted. Therefore, it is possible to prevent a problem that the motor driving device, the motor driving system including the motor driving device, and the motor of the electric vehicle continue to rotate.

  Further, the change of the command value D0 is monitored every control cycle after a predetermined period of time by steps # 51 to # 55, and the correction command value D1 is set to a value for stopping the motor 18 when there is no change in the command value D0 continuously. Gradually variable. Accordingly, the motor 18 can be stopped when the command value D0 becomes uncontrolled due to interruption or a bug. In addition, the motor 18 can be stopped by stopping the output of the command value D0 from the motor controller 11. Thereby, it is not necessary to perform communication for stopping the motor 18, and the communication load can be reduced.

  Further, when the command value D0 is changed within the control cycle after the motor is driven with the correction command value D1 in steps # 41 to # 46, the motor with the command value D0 is changed from the motor driving state with the previous correction command value D1. The motor is driven by a correction command value D1 obtained by correcting the command value D0 in a direction approaching the driving state. Therefore, sudden torque fluctuations of the motor 18 can be prevented.

  Further, since the motor controller 11 outputs the command value D0 by changing the minimum digit of the command value D0 when the command value D0 is the same as the command value D0 output last time, the same command value D0 is not output during normal operation. At this time, since the minimum digit of the command value D0 is within the error range, the operation of the motor 18 is not affected. The motor controller 11 may change and output the minimum digit of the subsequent command value D0 when the command value D0 is the same for a predetermined number of times.

  In the present embodiment, the predetermined value δ2 in step # 53 may be made smaller than the predetermined value δ1 in steps # 42 and # 45. Thereby, when there is no change in the command value D0, the motor 18 is gradually decelerated, and when there is a change, the motor 18 can be driven close to the desired command value D0 quickly.

  In addition, although the electric vehicle 1 equipped with the motor drive system 20 has been described, the same effect can be obtained for various devices using the motor drive system 20 that drives the motor 18.

  ADVANTAGE OF THE INVENTION According to this invention, it can utilize for the motor drive device and motor drive system which drive a motor. Moreover, it can utilize for apparatuses, such as an electric vehicle using a motor drive system.

The block diagram which shows the structure of the electric vehicle of embodiment of this invention. The block diagram which shows the structure of the motor drive module of the electric vehicle of embodiment of this invention. The flowchart which shows operation | movement of the motor controller of the electric vehicle of embodiment of this invention. The flowchart which shows operation | movement of the command value change detection part of the electric vehicle of embodiment of this invention. The flowchart which shows operation | movement of the command value correction | amendment part of the electric vehicle of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric vehicle 2 Main controller 3 Battery controller 4 Battery 5 Key 6 Throttle 7 Electrical system 8 Communication line 10 Motor drive device 11 Motor controller 12 Motor drive module 13 Command value change detection part 14 Command value correction part 15 Timer 16 Vector control part 17 Inverter 18 Motor 20 Motor drive system

Claims (6)

  In a motor drive device comprising: a motor controller that outputs a command value for driving a motor; and a motor drive module that drives a motor based on the command value, whether the command value has been changed or not. A command value change detecting unit for detecting the command value, and a command value correcting unit for correcting the command value. When the command value has not been changed within a predetermined period, the command value is corrected by the command value correcting unit. A motor drive device, wherein a correction command value corrected in a direction in which the motor decelerates is derived, and the motor is driven by the correction command value.   The command value correction unit monitors the detection result of the command value change detection means for each control cycle, and the command value correction unit displays the correction command value when the detection result is continuous and the command value is not changed. The motor driving device according to claim 1, wherein the motor driving device is gradually changed to a value for stopping the motor.   When the command value is changed within the next control cycle in which the motor is driven by the correction command value, the command is moved in a direction approaching the motor drive state by the command value from the motor drive state by the previous correction command value. The motor driving apparatus according to claim 2, wherein the motor is driven by the correction command value obtained by correcting the value.   4. The motor drive according to claim 1, wherein when the command value is the same as the command value output last time, the motor controller varies and outputs a minimum digit of the command value. 5. apparatus.   A motor drive system comprising: the motor drive device according to any one of claims 1 to 4; and a motor driven by the motor drive device.   6. A motor drive system according to claim 5, a main controller for transmitting a throttle opening to the motor controller, and a wheel rotated by the motor, wherein the command value corresponding to the throttle opening is set to the motor. An electric vehicle characterized in that the wheel is driven by output from a controller.

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