Method and device for actuating an electric machine in the motor starting mode

The present invention relates to a method (30) for actuating an electric machine (14) in the motor starting mode by means of a power electronic system (10), in particular for application in a motor vehicle, wherein the power electronic system (10) has a multiplicity of controllable power switches which are designed to supply the electric machine (14) with electric current (l_s), wherein a total amount of energy (50) which is required to reach a predefined rotational speed (n_crit) and a time period (t-0) for reaching the predefined rotational speed (n_crit) is estimated (38), wherein a setpoint torque (M) for starting the electric machine (14) is determined (42) on the basis of the estimated total amount of energy (50) and the estimated time (t-0), and wherein the power electronic system (10) is actuated (46) in accordance with the setpoint torque (M).