PROCESS AND DEVICE FOR CORRECTING THE FLOW DIRECTION OF THE MODEL FLOW OF A SENSOR-FREE, FIELD-ORIENTED ROTATING MAGNETIC FIELD MACHINE DOWN TO ZERO FREQUENCY

摘要

PCT No. PCT/EP96/03688 Sec. 371 Date Jun. 30, 1998 Sec. 102(e) Date Jun. 30, 1998 PCT Filed Aug. 21, 1996 PCT Pub. No. WO97/08820 PCT Pub. Date Mar. 6, 1997A method for correcting of the flux direction of a modelled flux vector down to zero frequency. The modelled flux vector is formed by a machine model as a function of a stator current vector and a stator voltage vector of a rotating-filed machine that has no sensors. A nominal (command) value for the field-forming (field-producing) and torque-forming current (torque-producing) component of the stator current vector of the rotating-field machine is determined. A current test vector is then added to the nominal (command) value of the field-forming (field-producing) current component. The current test vector has a profile that is non-constant with respect to time. The rotating-filed machine is driven into the saturation region, and the determined voltage vector of the rotating-filed machine is used to recover the response information of the rotor current vector, to which the test movement of the stator current vector is transferred. Thus, the inaccuracy of the so-called voltage model at low frequencies is corrected down to zero frequency, without interfering with the rotating filed machine.