The method for automatic control of the polyphase machine (2) supplied from the DC source (Ud) through the inverter (1) involves the inverter controlling the stator magnetic flux ( psi s). If the amount ( DELTA psi s) by which the magnetic flux changes exceeds a first limit ( DELTA psi sr) it is reduced. Alternatively the change in the magnetic flux can only be reduced if the addition to the change in flux ( DELTA psi s) there is a change (Ud) in the DC voltage which exceeds a second limit ( DELTA Ur). As a measure of the change ( DELTA U) the differences in amplitude of the DC voltage (Ud) and its value (UF) if it is delayed can be used.
