Method for controlled application of a stator current set point value and of a torque set point value for a converter-fed rotating-field machine

Abstract

The invention relates to a method for the controlled application of a stator-current target value (ISnom) and a torque target value (Mnom) for a polyphase machine (4) that is supplied by an electronic power converter. According to the invention: current components (ISdnom, ISqnom) in a co-ordinate system (d, q) with a fixed rotor flux or rotating magnetic pole are calculated in accordance with a torque target value and in asynchronous machines in accordance with a rotor-flux target value (ψRnom), a calculated rotor-flux actual value (ψ<SB>R</SB>) or a rotating magnetic-pole flux; a stator-circuit frequency (ω<SB>S</SB>) is determined; a terminal-flux target value (ψKnom) is calculated in accordance with the values (ISnom, ISqnom, ψ<SB>R</SB>, ω<SB>S</SB>) by means of the machine parameters (L, R<SB>S</SB>), said terminal-flux target value being subsequently projected onto a flux-course curve, selected from stored, off-line optimised flux-course curves. This permits the state of the stator current (I<SB>S</SB>) to be regulated in relation to the rotor flux (ψ<SB>R</SB>) or rotating magnetic-pole flux by means of momentary values, facilitating a stationary and dynamic precise control of motor currents (I1,I2,I3) and thus the torques (M) of a polyphase machine (4).

Dependencies are inferred from the claim text.