Method for regulating an asynchronous machine, which is supplied by means of a current-impressing intermediate circuit converter, in the field-suppression range

摘要

The method described in the prior application for use with voltage-impressing pulse converters is modified for use with current-impressing intermediate-circuit converters. The indirect flux and speed regulation constructed in accordance with the prior application specifies the spatial angle of the stator current vector. An invertor controller, which is designed predominantly digitally, causes the angle of the actual value vector to follow the desired angle as quickly as the maximum switching frequency of the invertor allows. If the frequency falls below an adjustable minimum frequency, the controller carries out the intermediate-phase pulsing, which is known per se, in order to reduce the torque ripple. The angle error occurring as a result of the commutation delay and the commutation itself is corrected after every commutation. <IMAGE>