Motor Controller, Electric Power Steering Device Using the Motor Controller, and Vehicle Using the Motor Controller

Patent metadata

Field	Value
Publication number	US-2016200355-A1
Application number	US-201314911697-A
Country	US
Kind code	A1
Filing date	Dec 13, 2013
Priority date	Aug 12, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

A motor controller, an electric power steering device using the motor controller, and a vehicle using the motor controller are provided. The motor controller includes plural hardware sets configured to operate in a normal state and to output a motor current, a control operation device configured to control the plurality of hardware sets commonly, an electric motor configured to operate with motor current output from each of the plurality of hardware sets, and an abnormality diagnosis unit configured to diagnose an abnormality of each of the plurality of hardware sets. In the control device, when there is an abnormal hardware set that has been diagnosed by the abnormality diagnosis unit, the control operation device stops an operation of the abnormal hardware set that has been diagnosed, and continues driving of the electric motor with a normal hardware set.

First claim

1 . A motor controller comprising:
a plurality of hardware sets configured to operate in a normal state and to output a motor current; a control operation device configured to control the plurality of hardware sets commonly; an electric motor configured to operate with motor current output from each of the plurality of hardware sets; and an abnormality diagnosis unit configured to diagnose an abnormality of each of the plurality of hardware sets, wherein when there is an abnormal hardware set that has been diagnosed by the abnormality diagnosis unit, the control operation device stops an operation of the abnormal hardware set that has been diagnosed, and continues driving of the electric motor with a normal hardware set.

2 . (canceled)

3 . (canceled)

4 . The motor controller according to claim 1 ,
wherein the abnormality diagnosis unit comprises a hardware state change amount operation unit configured to calculate a state change amount of a hardware set from a difference in detection value detected at the plurality of hardware sets or a difference between the detection value detected at the plurality of hardware sets and a threshold, wherein the control operation device determines that the state change amount falls within the variation, when the state change amount of the hardware set is smaller than a predefined value, and wherein the control operation device changes a control parameter for the plurality of hardware sets depending on the state change amount of the hardware set, when the state change amount of the hardware set is equal to or larger than the predefined value.

5 . A motor controller that drives and controls a multiphase electric motor,
the motor controller comprising: a plurality of motor drive circuits configured to supply multiphase motor drive current to multiphase motor windings of the multiphase electric motor; a control operation device configured to drive and control the plurality of motor drive circuits; a plurality of motor current cutoff units respectively arranged between the plurality of motor drive circuits and the multiphase motor windings; and an abnormality detection unit configured to detect an abnormality of at least one of the plurality of motor drive circuits, wherein when the abnormality detection unit does not detect the abnormality, the control operation device controls the plurality of motor drive circuits to supply the multiphase motor drive current to the multiphase motor windings, and wherein when the abnormality detection unit detects the abnormality, the control operation device cuts off any of the plurality of motor current cutoff units connected to any of the plurality of motor drive circuits where the abnormality occurs.

6 . The motor controller according to claim 5 ,
wherein the abnormality detection unit detects the abnormality of at least one of the plurality of motor drive circuits and the plurality of multiphase electric motor, wherein in the multiphase electric motor, the multiphase motor windings that are wound around a stator are respectively connected in parallel with a plurality of coil units, and wherein when the abnormality detection unit detects the abnormality, the control operation device changes a drive mode of driving the plurality of motor drive circuits depending on an abnormality mode.

7 . The motor controller according to claim 5 ,
wherein each of the plurality of motor drive circuits includes a multiphase inverter circuit having at least one upper arm and at least one lower arm having a number of arms corresponding to the number of phases of the multiphase electric motor, and configured to supply the multiphase motor drive current to the multiphase electric motor, and wherein the abnormality detection unit detects at least one of an open failure or a short-circuit failure of the at least one upper arm and the at least one lower arm included in the plurality of motor drive circuits.

8 . (canceled)

9 . The motor controller according to claim 5 , wherein the abnormality detection unit comprises:
an upper current detection resistance arranged on a positive-side power supply line to which the at least one upper arm are connected; a lower current detection resistance arranged on a negative-side power supply line to which the at least one lower arm are connected; and a plurality of current detection units configured to individually detect a voltage between terminals of the upper current detection resistance and the lower current detection resistance.

10 . (canceled)

11 . (canceled)

12 . The motor controller according to claim 6 ,
wherein the abnormality detection unit detects a disconnection abnormality of at least one of the plurality of coil units included in the multiphase motor windings of the multiphase electric motor, and wherein when the abnormality detection unit detects the disconnection abnormality of at least one of the plurality of coil units, the control operation device corrects and increases a current control gain for one of the multiphase motor windings at which the disconnection abnormality occurs in order to suppress a torque change.

13 . The motor controller according to claim 6 ,
wherein the abnormality detection unit detects a disconnection abnormality of at least one of the plurality of coil units included in the multiphase motor windings of the multiphase electric motor, and wherein when the abnormality detection unit detects the disconnection abnormality of at least one of the plurality of coil units, the control operation device reduces a back electromotive voltage compensation gain in order to compensate a drop of a back electromotive voltage.

14 . (canceled)

15 . The motor controller according to claim 5 ,
further comprising a motor angle detection unit configured to detect a motor rotational angle of the multiphase electric motor, wherein the control operation device comprises:
an instruction value operation unit configured to output an instruction value for driving the multiphase electric motor; and a multiphase current instruction value operation unit configured to calculate a multiphase current instruction value base on an instruction value output from the instruction value operation unit and the motor rotational angle detected by the motor angle detection unit.

16 . (canceled)

17 . The motor controller according to claim 5 , further comprising:
a plurality of overcurrent determination units configured to individually determine whether or not each of the current values detected by the plurality of current detection units is in an overcurrent state where the current value exceeds an overcurrent threshold; and a plurality of current bypass circuits connected between a power supply system that individually supplies power to the plurality of motor drive circuits and the ground, wherein each of the plurality of current bypass circuits comprises a switch unit, and wherein when a determination result of any one of the plurality of overcurrent determination units is the overcurrent state, the switch unit is controlled to be in the on state.

18 . (canceled)

19 . (canceled)

20 . (canceled)

21 . The motor controller according to claim 5 , wherein a protection circuit configured to suppress a short-circuit current is arranged between the plurality of motor drive circuits.

22 . The motor controller according to claim 5 further comprising:
a motor current cutoff diagnosis unit configured to diagnose an operation state of

Assignees

• Nsk Ltd

Inventors

• Mori Kenji
• Tagami Kotaro
• Sugawara Hiroki
• Shinohara Shigeo
• Sekine Takaaki
• Senba Takeshi
• Endo Shuji

Classifications

• B62D5/0463

  calculating assisting torque from the motor based on driver input · CPC title

• G01R31/343

  in operation · CPC title

• H02P5/74

  controlling two or more AC dynamo-electric motors (H02P5/46, H02P5/60 take precedence) · CPC title

• B62D5/0484 Primary

  for reaction to failures, e.g. limp home · CPC title

• H02P29/032

  Preventing damage to the motor, e.g. setting individual current limits for different drive conditions · CPC title