Induction motor control method
AssigneeFord Motor Company
InventorsDoug Deng, Xingyi Xu
Life of this patent
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Abstract
In one embodiment of the present invention, a control method for an induction motor includes calculating a desired quadrature-axis voltage and a desired direct-axis voltage according to both current control and voltage control. Below a predetermined motor speed, the motor is controlled in accordance with current control only. Above that predetermined speed, the two desired quadrature-axis voltages are combined in relative proportions, with the influence of voltage control being greater with higher motor speed. The two desired direct-axis voltages are likewise combined. The influence of voltage control thus increases with increasing motor speed. Above a second motor speed threshold, the motor is controlled in accordance with voltage control only.
Claims8
A control method for an induction motor comprising the steps of:
- (a) calculating desired variables for control of said motor according to voltage control;
- (b) calculating desired variables for control of said motor according to current control;
- (c) applying said desired variables calculated according to voltage control and said desired variables calculated according to current control in relative proportions to control said motor;
- wherein said relative proportions are functions of a motor operating condition.
A control method for an induction motor comprising the steps of:
- (a) calculating a first desired quadrature-axis voltage and a first desired direct-axis voltage based on voltage control;
- (b) calculating a second desired quadrature-axis voltage and a second desired direct-axis voltage based on current control;
- (c) combining said first desired quadrature-axis voltage and said second desired quadrature-axis voltage in relative proportions to generate a commanded quadrature-axis voltage;
- (d) combining said first desired direct-axis voltage and said second desired direct-axis voltage in relative proportions to generate a commanded direct-axis voltage;
- and
- (e) applying said commanded direct-axis voltage and said commanded quadrature-axis voltage to control said induction motor.
Dependencies are inferred from the claim text.