| 摘要 |
1. Device for regulating the rotational sped and/or torque of an asynchronous machine (ASM) which is fed with impressed current by an indirect direct-current converter (GR, L, WR), containing a current control loop (Si, Ri, StG) which acts on the rectifier section (GR) of the converter, a current-angle control loop which contains a current-angle summing section (Sg) for forming the difference between the nominal value and the actual value of the current-angle, a current-angle regulator (Rg) which derives, from the nominal-value/actual-value difference of the current angle the reference variable for the frequency of the stator current (I1 ) at the output of the inverter section (WR) and involving a transformation of coordinates in which the signals for the air-gap flux (vphi soll ) and rotational speed or torque (Msoll ) are transformed from the rectangular system of coordinates into the polar system of coordinates, characterised in that a gamma discriminator (GD) determines, by detecting the phase shift (phi) between the stator current (I1 ) and the stator voltage (U1 ) of the asynchronous machine (ASM), the current angle (gamma i,ist ) between the air-gap flux vector (vphi) and the stator current vector (I1 ) in approximation as the difference between 90 degrees and the angle of phase shift (phi) and that the difference variable (fi ist ) for the inverter section (WR) is simultaneously the actual value in a high order control loop for the rotational speed or torque of the asynchronous machine (ASM). |
