초록 ▼

In an induction motor drive a signal representative of the torque T as derived by sensing only the stator armature current I, and the slip frequency f2 and by calculating instantaneously T=I12 F, where F is a function of f2/R2, where R2 is the rotor resistance of the motor. The value of R2 is adjust

In an induction motor drive a signal representative of the torque T as derived by sensing only the stator armature current I, and the slip frequency f2 and by calculating instantaneously T=I12 F, where F is a function of f2/R2, where R2 is the rotor resistance of the motor. The value of R2 is adjusted to match temperature by generally two alternative methods: (1) measuring the stator temperature, relying on the change of resistance R1, known experimentally, and applying an equivalent change for the rotor resistance R2; (2) by running the motor at rated speed and determining experimentally R2/f2 as a function of F.

대표청구항 ▼

Apparatus for the determination of the torque of a rotating induction motor including p pairs of poles, having a rotor leakage inductance L2, a magnetizing inductance LM and a rotor resistance R2, comprising: first sensing means for deriving a first signal representative of the stator current I1; se

Apparatus for the determination of the torque of a rotating induction motor including p pairs of poles, having a rotor leakage inductance L2, a magnetizing inductance LM and a rotor resistance R2, comprising: first sensing means for deriving a first signal representative of the stator current I1; second sensing means for deriving a second signal representative of the slip angular frequency w2 of the motor; first combining means responsive to said first signal for providing a third signal representative of I12; and second combining means responsive to said second signal and to said third signal for deriving a signal representative of the instantaneous torque T in accordance with the formula: T = [Figure]