MOTOR CONTROLLER

• US 20070290639A1
• Filed: 05/31/2007
• Published: 12/20/2007
• Est. Priority Date: 05/31/2006
• Status: Abandoned Application

• Current Assignee: NSK Limited
• Original Assignee: NSK Limited
• Inventors: Mori, Kenji
• Application Number:
  US11/755,770
• Publication Number:
  US 20070290639A1
• Time in Patent Office: Days
• US Class Current: 318/400.42
• CPC Class Codes: B62D 5/046 Controlling the motor
• CPC Class Codes: H02P 6/28 Arrangements for controlling current H02P6/10 takes precedence

Abstract

This invention provides a motor controller that can reduce the influence of noisy sound and a torque ripple due to noise. A current command value calculating unit 3 respectively outputs current command values of n phases of an n-phase brushless motor 7. n current deviation calculating units 22a to 22c calculate current deviations between phase currents respectively detected in current detecting units 8a to 8c and the current command values of the n phases. A corrected value calculating unit 24 calculates an average value of the current deviations of the n phases as a corrected value. A current control unit 4 subtracts the corrected value from the current deviations outputted from the n−1 current deviation calculating units of the n current deviation calculating units and then controls the currents to output voltage command values of the n−1 phases. A voltage command value calculating unit 27 calculates a voltage command value of remaining one-phase from the voltage command values of the n−1 phases. The calculated voltage command values of the n phases are supplied to a motor driving unit.

Claims

1. A motor controller that drives and controls a brushless motor having n phases, n being an integer of 3 or more, in a motor driving circuit, the motor controller comprising:

a motor current detecting unit that detects phase currents of the brushless motor respectively;

a current command value calculating unit that respectively outputs current command values of the n phases of the brushless motor;

n current deviation calculating units that calculate current deviations between the phase currents respectively detected in the current detecting unit and the phase current command values respectively outputted from the current command value calculating unit;

a corrected value calculating unit that calculates an average value of the current deviations of the n phases outputted from the current deviation calculating units as a corrected value;

a current control unit that subtracts the corrected value calculated in the corrected value calculating unit from the current deviations outputted from the n−

1 current deviation calculating units of the n current deviation calculating units and then controls the currents to output voltage command values of n−

1 phases; and

a voltage command value calculating unit that calculates a voltage command value of remaining one-phase from the voltage command values of the n−

1 phases outputted from the current control unit,

wherein the voltage command values of the n phases calculated in the voltage command value calculating unit are supplied to a motor driving unit.

2. The motor controller according to claim 1, wherein the current deviation calculating units have current deviation adjusting units that carry out an adjusting process with a quantization error to input the outputs of the current deviation adjusting units to the corrected value calculating unit.

3. The motor controller according to claim 2, wherein the adjusting process with the quantization error includes at least one of a smoothing process, a phase compensating process and a gain adjusting process of the n current deviations.

4. The motor controller according to claim 3, wherein the current deviation adjusting units carry out at least one of the smoothing process for suppressing an oscillation of the current deviation, the phase compensating process and the gain adjusting process.

5. The motor controller according to claim 1, wherein the current deviation calculating units have command value adjusting units that carry out at least one of a smoothing process, a phase compensating process and a gain adjusting process with respect to the current command values of the n phases outputted from the current command value calculating unit to calculate deviations between outputs of the command value adjusting units and the current detected values of the n phases detected in the current detecting unit.

6. The motor controller according to claim 1, further comprising:

a counter electromotive voltage calculating unit that calculates the counter electromotive voltage of each phase of the brushless motor; and

a counter electromotive voltage adding unit that individually adds n phase voltages outputted from the current control unit and the voltage command value calculating unit to n phase counter electromotive voltages of the counter electromotive voltage calculating unit to output results to the motor driving circuit.