Abstract: A method for operating an electric machine including a rotor and a stator is connected to a first or a second power electronics assembly (PEA), the first or the second PEA including a circuit arrangement that produces a freewheeling condition or an active short circuit condition for a winding of the rotor or the stator, to a DC voltage network having a battery, and the first or the second PEA including an inverter formed by the circuit arrangement. The method includes, in response to a primary fault signal indicating a fault the first or the second PEA, actuating the first or the second PEA to produce the freewheeling condition, and in response to a secondary fault signal indicating a nonreceptiveness of the battery for power fed by the electric machine to the DC voltage network, actuating both the first and the second PEA to produce the active short circuit condition.

Abstract: An inverter device of an electric drive device may be configured to convert a direct voltage of an intermediate circuit of the electric drive device into a multi-phase alternating current to operate an electric motor of the electric drive device. A safety signal may be received by a control unit of the electric drive device, which instructs the control unit to operate the electric motor in a safe operating mode and to discharge the intermediate circuit at same time. If an active short circuit mode is preset, the inverter device is controlled to operate the electric motor in the active short circuit mode and to discharge the intermediate circuit in the discharge mode. If a freewheel mode is preset, the inverter device is controlled to operate the electric motor in the freewheel mode and, upon satisfaction of a current criterion, controlled to discharge the intermediate circuit in the discharge mode.

Abstract: A method for operating an electrical circuit arrangement comprising an electrical circuit and an electrical machine, wherein when at least one triggering criterion is fulfilled the electrical machine is switched via the electrical circuit to a freewheeling, after which a time duration is determined in dependence on at least one measurement value describing a change in the stator current in the electrical machine, and the electrical machine is operated in the freewheeling for this duration and then it is switched via the electrical circuit to an active short circuiting.