| 摘要 |
PURPOSE:To control a rotating speed and a torque by only the current sensor of a motor, by a method wherein the output voltages of the components of respective axes are controlled so that the primary currents of the components of respective axes coincide with a commanding value, in an orthogonal d-q axes coordinate system rotating in the synchronous angle frequency of an induction motor. CONSTITUTION:The differential value omega of a (q)-axis current detecting value (i)1d, which is differentiated by a differentiator 15, is subtracted from a primary angle frequency omega1 and the subtracted value omega1' is inputted into an oscillator 14 whereby the voltage phase reference signal theta of a sine wave signal, having a frequency proportional to the subtracted value omega1' and constant in the amplitude thereof, is obtained. A value v in accordance with a difference between the (d)-axis component commanding value (i)1d' of an exciting current and a (d)-axis component detecting value (i)1d is outputted from an exciting current regulator 8 to add it to an output voltage commanding value V1d, operated by a (d)-axis component. Further, another value Vq obtained by multiplying the output value v of the exciting current regulator 8 by the proportional gain Kv of a counter 9 is added to an output voltage commanding value Vlq operated by a (q)-axis component. According to this method, the fluctuation of the magnetic flux of a motor, which is due to the abrupt change of a torque, error in the voltage control of a converter or the like may be prevented. |
