The invention relates to a method for operating an electric machine (1), in particular of a motor vehicle, that has a stator (4) and a rotor (2), wherein the stator (4) has a stator winding (5) having at least three phases (U, V, W), and wherein the rotor is arranged/arrangeable on a rotor shaft (3), wherein a time-invariant differential equation modelling the machine (1) is taken as a basis for ascertaining a desired current value (Idesired,fl) for the stator winding (5) for producing a required torque and/or a required rotation speed, wherein the desired current value (Idesired,fl) is compared with an actual current value (Iactual,fl) of the stator winding (5), which actual current value corresponds to electric phase currents (IU, IV, IW) flowing through the phases (U, V, W), and wherein the comparison is taken as a basis for passing current through the phases (U, V, W) such that a difference from the actual current value (Iactual,fl) to the desired current value (Idesired,fl) is reduced. There is provision for the time-invariant differential equation to be ascertained on the basis of a periodic, linear differential equation by means of a Floquet transformation.