Abstract: A vehicle includes a drive motor with electrically upstream electric converter, a drive controller generating converter control signals actuating the converter for driving and normal braking operation, and an immobilizer electrically connected between the converter and the drive controller preventing converter control signals which would produce a driving operation of the drive motor from being forwarded to the converter when the vehicle is stopped, in particular at a stop. An alternate regulating device and a monitoring device allow activation of a special braking mode in the presence of an emergency braking command and in the event of which the drive controller is deactivated or at least signal flows of converter control signals of the drive controller to the immobilizer are interrupted, the immobilizer is activated, and converter control signals producing braking operation of the drive motor are transmitted to the converter through the immobilizer by the alternate regulating device.

Abstract: A method for operating switching elements of an inverter of a vehicle that is driven by way of a three-phase synchronous machine. The inverter has a series circuit of switching elements for the phases. When the vehicle brakes, the synchronous machine is used to set a cycle rate for the operation of the switching elements depending on a frequency of AC phase currents of the synchronous machine. The electrical energy provided by the synchronous machine is fed to a DC voltage intermediate circuit. The cycle rate is set according to the frequency of the AC phase currents, such that it corresponds to the frequency of the respective AC phase currents of the synchronous machine. Zero points of the AC phase currents are determined, and the switching elements are operated to set a predefined phase difference between the respective AC phase current and a respectively associated AC phase voltage.

Abstract: A vehicle includes a drive motor with electrically upstream electric converter, a drive controller generating converter control signals actuating the converter for driving and normal braking operation, and an immobilizer electrically connected between the converter and the drive controller preventing converter control signals which would produce a driving operation of the drive motor from being forwarded to the converter when the vehicle is stopped, in particular at a stop. An alternate regulating device and a monitoring device allow activation of a special braking mode in the presence of an emergency braking command and in the event of which the drive controller is deactivated or at least signal flows of converter control signals of the drive controller to the immobilizer are interrupted, the immobilizer is activated, and converter control signals producing braking operation of the drive motor are transmitted to the converter through the immobilizer by the alternate regulating device.

Abstract: A method for operating switching elements of an inverter of a vehicle that is driven by way of a three-phase synchronous machine. The inverter has a series circuit of switching elements for the phases. When the vehicle brakes, the synchronous machine is used to set a cycle rate for the operation of the switching elements depending on a frequency of AC phase currents of the synchronous machine. The electrical energy provided by the synchronous machine is fed to a DC voltage intermediate circuit. The cycle rate is set according to the frequency of the AC phase currents, such that it corresponds to the frequency of the respective AC phase currents of the synchronous machine. Zero points of the AC phase currents are determined, and the switching elements are operated to set a predefined phase difference between the respective AC phase current and a respectively associated AC phase voltage.