A method is specified for operating a rotating electrical machine, in
which the rotating electrical machine is connected in terms of phase to a
converter circuit, having a DC voltage circuit, for connecting at least
two voltage levels, and the phases of the converter circuit are connected
to the DC voltage circuit in accordance with a selected switching state
combination of switching states for power semiconductor switches in the
converter circuit. In order to reduce the switching frequency of the
power semiconductor switches, a prediction is made of the further
behavior of the overall system and according to this prediction, the
optimum switching state combination is selected starting from the
preceding selected switching state combination and with respect to the
number of transitions from the preceding selected switching state
combination to the selected switching state combination and with respect
to the respective predetermined value range for the torque of the
rotating electrical machine, for the magnetic stator flux of the rotating
electrical machine and for the potential at the subconnection.