초록 ▼

An induction motor vector control apparatus calculates a slip factor using a secondary time constant. A reference signal is added as noise to the excitation current command signal. The secondary time constant is brought closer to its actual value by modifying the secondary time constant in a directi

An induction motor vector control apparatus calculates a slip factor using a secondary time constant. A reference signal is added as noise to the excitation current command signal. The secondary time constant is brought closer to its actual value by modifying the secondary time constant in a direction zeroing the correlation between the motor speed feedback signal and the reference signal.

대표청구항 ▼

An apparatus for vector control of an adjustable-speed induction motor, including a motor drive circuit for applying power to drive the motor, and a control circuit responsive to a torque command signal, an excitation current command signal and a slip frequency for controlling the operation of the m

An apparatus for vector control of an adjustable-speed induction motor, including a motor drive circuit for applying power to drive the motor, and a control circuit responsive to a torque command signal, an excitation current command signal and a slip frequency for controlling the operation of the motor drive circuit so as to vary the power to the motor, the control circuit including: a speed sensor sensitive to motor rotation speed for producing a speed feedback signal indicative of a sensed speed of rotation of the motor; a source for producing a speed command signal indicative of a desired motor speed; a source for producing an excitation current command signal indicative of a desired motor excitation current; a source for producing a reference signal; means for summing the speed feedback signal and the speed command signal to provide a speed error signal indicative of the difference between the sensed and desired motor speeds; means for converting the speed error signal into the torque command signal; means for adding the reference signal to the excitation current command signal applied to the control circuit; means responsive to the excitation current command signal and the torque command signal for calculating the slip frequency using a secondary time constant; means for calculating a correlation coefficient indicative of a mutual relation between the speed error signal and the reference signal; and means for modifying the secondary time constant, in accordance with the correlation coefficient, in a direction zeroing the correlation coefficient.