Method for operating an electric machine, especially in a motor vehicle, and a motor vehicle

A motor vehicle, comprising:

• a control device;
• a Direct Current (DC) voltage network;
• a battery connected by a circuit arrangement having battery contactors to the DC voltage network;
• and
• an electric machine including a rotor and a stator,
• wherein at least one of the rotor or the stator is connected to at least one of a first power electronics assembly or a second power electronics assembly actuated by way of the control device,
• wherein the first power electronics assembly and the second power electronics assembly are included in the DC voltage network,
• wherein the circuit arrangement having battery contactors is different from the first power electronics assembly and the second power electronics assembly included in the DC voltage network,
• wherein the at least one of the first power electronics assembly and the second power electronics assembly includes a circuit arrangement by which a freewheeling condition and an active short circuit condition can be produced for a winding of the rotor and the stator, to the DC voltage network,
• wherein one of the first power electronics assembly or the second power electronics assembly includes an inverter formed by the circuit arrangement,
• wherein the control device, in response to a primary fault signal indicating a fault, actuates at least one of first power electronics assembly or the second power electronics assembly to produce the freewheeling condition for the rotor and the stator, and
• wherein the control device, after the freewheeling condition is produced for the rotor and the stator, checks for presence of a secondary fault signal indicating a nonreceptiveness of the battery for power fed by the electric machine to the DC voltage network due to an opening of the battery contactors of the circuit arrangement while the primary fault signal continues to indicate the fault,
• wherein the control device, in response to determining that the secondary fault signal indicating the nonreceptiveness of the battery for power fed by the electric machine to the DC voltage network due to the opening of the battery contactors of the circuit arrangement is present while the primary fault signal continues to indicate the fault, actuates the first power electronics assembly and the second power electronics assembly to produce the active short circuit condition.