Method for the control of an asynchronous machine supplied from a converter in the operation of weakening of field

摘要

A method of control-regulation of a converter-fed async machine in the shunted-field drive mode, in particular for controlling a drive for a hoist or lifting mechanism, aims at providing stable drive in the shunt-field drive mode e.g, on the basis of speed control (revs.), and thus with a speed requirement in the shunt-field region for `motor lift' and/or `generator drop' the following steps are carried out (a) initially the nominal speed (revs) is increased, (b) a max. desired speed (revs.) is determined for a arbitrarily defined stator current characteristic, if the slip frequency is less than the threshold value and (c) this desired speed is stored until the next shut-down or reversing phase. IMAGE