Method of controlling a motor and device therefor

• US 20030169012A1
• Filed: 02/21/2003
• Published: 09/11/2003
• Est. Priority Date: 02/21/2002
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nakazawa, Yosuke
• Granted Patent: US 6,828,750 B2
• Time in Patent Office: Days
• US Class Current: 318/701
• CPC Class Codes: H02P 21/22 Current control, e.g. using a current control loop
• CPC Class Codes: H02P 25/08 Reluctance motors

Abstract

A control device supplies an operating voltage instruction to a PWM inverter that drives a motor and, if the inferred axis of the rotor permanent magnet flux direction is defined as the dr axis, the direction orthogonal to the dr axis as the qr axis, and an axis offset by a predetermined angle from said dr axis as the γ axis, on the γ axis, the inferred γ axis voltage value which is inferred and calculated by using the detected value of the motor current and motor equivalent circuit constant and the γ axis component voltage applied to the motor are compared, and the dr axis phase difference is inferred and calculated so that the deviation of these becomes substantially zero.

Claims

1. A method of controlling a reluctance torque/permanent magnet motor which has a rotor with a protuberant magnetic polarity, comprising the steps of:

comparing on a γ

axis an inferred voltage of said γ

axis, which is inferred and calculated by using a detected value of a motor current and a motor equivalent circuit constant and a γ

axis component voltage applied to a motor, if an inferred axis of a rotor permanent magnet flux direction is defined as a dr axis, a direction orthogonal to said dr axis as a qr axis, and an axis offset by a predetermined angle from said dr axis as said γ

axis; and

inferring and calculating a phase difference (a phase angle) of said dr axis so that a deviation thereof substantially becomes zero.

2. The method of controlling a motor according to claim 1,

wherein said phase difference δ

of said γ

axis and said dr axis is variable in response to a torque instruction.

3. The method of controlling a motor according to claim 1,

wherein said phase difference δ

of said γ

axis and said dr axis is variable in response to dr and qr axis current instructions.

4. A method of controlling a reluctance torque/permanent magnet motor which has a rotor with a protuberant magnetic polarity, comprising the steps of:

comparing on a γ

axis an inferred current value of said γ

axis, which is inferred and calculated by using a voltage that is applied to a motor and a motor equivalent circuit constant and a detected current value of said γ

axis, if an inferred axis of a rotor permanent magnet flux direction is defined as a dr axis, a direction orthogonal to said dr axis as a qr axis, and an axis offset by a predetermined angle from said dr axis as said γ

axis; and

inferring and calculating a phase difference (a phase angle) of said dr axis so that a deviation thereof substantially becomes zero.

5. The method of controlling a motor according to claim 4, wherein said phase difference δ

of said γ

axis and said dr axis is variable in response to a torque instruction.

6. The method of controlling a motor according to claim 4,

wherein said phase difference δ

of said γ

axis and said dr axis is variable in response to dr and qr axis current instructions.

7. A method of controlling a reluctance motor which has a rotor with a protuberant magnetic polarity, comprising the steps of:

comparing on a γ

axis an inferred voltage of a γ

axis, which is inferred and calculated by using a detected value of a motor current and a motor equivalent circuit constant and a γ

axis component voltage applied to a motor, if an inferred axis of a rotor permanent magnet flux direction is defined as a dr axis, a direction orthogonal to said dr axis as a qr axis, and an axis offset by a predetermined angle from said dr axis as said γ

axis; and

inferring and calculating a phase difference (a phase angle) of said dr axis so that a deviation thereof substantially becomes zero.

8. A method of controlling a reluctance motor which has a rotor with a protuberant magnetic polarity, comprising the steps of:

comparing on a γ

axis an inferred current value of said γ

axis, which is inferred and calculated by using a voltage that is applied to a motor and a motor equivalent circuit constant and a detected current value of said γ

axis, if an inferred axis of a rotor permanent magnet flux direction is defined as a dr axis, a direction orthogonal to said dr axis as a qr axis, and an axis offset by a predetermined angle from said dr axis as said γ

axis; and

inferring and calculating a phase difference (a phase angle) of said dr axis so that a deviation thereof substantially becomes zero.

9. A motor control device that supplies an operating voltage instruction to an inverter section for driving a motor, comprising:

means for comparing on a γ

axis, an inferred γ

axis voltage value which is inferred and calculated by using a detected value of a motor current and a motor equivalent circuit constant and a γ

axis component voltage applied to said motor, where an inferred axis of a rotor permanent magnet flux direction is defined as a dr axis, a direction orthogonal to said dr axis as a qr axis, and an axis offset by a predetermined angle from said dr axis as said γ

axis; and

means for inferring and calculating said dr axis phase difference so that a deviation of said γ

axis inferred voltage value and said γ

axis component voltage obtained by said means for comparing becomes substantially zero.

10. A motor control device that supplies an operating voltage instruction to an inverter section for driving a motor, comprising:

means for comparing, on a γ

axis, an inferred γ

axis current value which is inferred and calculated by using a voltage applied to said motor and motor equivalent circuit constant and a detected current value of said γ

axis, where an inferred axis of a rotor permanent magnet flux direction is defined as a dr axis, a direction orthogonal to said dr axis as a qr axis, and an axis offset by a predetermined angle from said dr axis as said γ

axis; and

means for inferring and calculating a dr axis phase difference so that a deviation of said inferred current value of said γ

axis and a detected value of said γ

axis obtained by said means for comparing becomes substantially zero.