Claims
- 1. A method of establishing a reference current for use in operating a synchronous motor, comprising the steps of:
- (a) obtaining a torque-angle profile of the motor;
- (b) obtaining an excitation component and a reluctance component of the torque-angle profile;
- (c) establishing a phase current from the excitation component and the reluctance component of the torque-angle profile;
- (d) establishing a delay angle of the phase current;
- (e) establishing a reference torque from the delay angle, the phase current, and the excitation component and reluctance component of the torque-angle profile; and
- (f) establishing a reference current from the reference torque.
- 2. The method of claim 1, wherein the excitation component and the reluctance component of the torque-angle profile are obtained using spectral analysis.
- 3. The method of claim 2, wherein the spectral analysis includes Fourier analysis.
- 4. A method of operating a synchronous motor in accordance with a torque command and an excitation component and reluctance component of a torque-angle profile of the motor, comprising the steps of:
- (a) establishing a phase current from the excitation component and the reluctance component of the torque-angle profile;
- (b) establishing a delay angle of the phase current;
- (c) establishing a reference torque from the delay angle, the phase current, and the excitation component and reluctance component of the torque-angle profile;
- (d) establishing the reference current from the reference torque;
- (e) comparing the reference current with a feedback current to generate a switching signal;
- (f) generating a drive current in accordance with the switching signal; and
- (g) supplying the motor with the drive current.
- 5. Apparatus for establishing a reference current for use in operating a synchronous motor, comprising:
- (a) means for obtaining a torque-angle profile of the motor;
- (b) means for obtaining a reluctance component of the torque-angle profile;
- (c) means for establishing a phase current from the excitation component and the reluctance component of the torque-angle profile;
- (d) means for establishing a delay angle of the phase current;
- (e) means for establishing a reference torque from the delay angle, the phase current, and the excitation component and reluctance component of the torque-angle profile; and
- (f) means for establishing a reference current from the reference torque.
- 6. Apparatus for operating a synchronous motor in accordance with a torque command and an excitation component and reluctance component of a torque-angle profile of the motor, comprising:
- (a) a controller for establishing a reference current from the torque command and the excitation component and reluctance component of the torque-angle profile, said controller including:
- (1) means for establishing a phase current from the excitation component and the reluctance component of the torque-angle profile;
- (2) means for establishing a delay angle of the phase current;
- (3) means for establishing a reference torque from the delay angle, the phase current, and the excitation component and reluctance component of the torque-angle profile; and
- (4) means for establishing the reference current from the reference torque;
- (b) a current regulator for comparing the reference current with a feedback current to generate a switching signal; and
- (c) an inverter for generating a drive current in accordance with the switching signal and for supplying the motor with the drive current.
- 7. The apparatus of claim 6, wherein the inverter includes a plurality of switching devices and a nonzero return neutral current path to the synchronous motor.
Parent Case Info
This application is a continuation of application Ser. No. 08/103,517 filed Aug. 9, 1993, now abandoned.
US Referenced Citations (11)
Continuations (1)
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Number |
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103517 |
Aug 1993 |
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