Robert Boschgmbh

Ekard Grossmann

Daniel Raichle

Torsten Heidrich

Marcus Abele

The invention relates to a method () for discharging a high-voltage intermediate circuit () with a discharge circuit (), wherein the high-voltage intermediate circuit () comprises an intermediate circuit capacitor (), having the steps of: ascertaining () the voltage (U_ZK) of the high-voltage intermediate circuit (); and actuating () the discharge circuit () on the basis of the ascertained voltage (U_ZK).

Method and device for discharging a high-voltage intermediate circuit of a vehicle with a discharge unit

The invention relates to a method and to a device for changing from the idle operating state of an electric motor () having three phase terminals (---) to a short-circuit operating state. Thereby significant voltage rises are avoided. For this purpose, after receiving () a request for changing of the operating state of the electric motor () to the short-circuit operating state, three switching elements (---) are closed. Thereby the switching elements (---) are at least partially closed successively and the times of closing the individual switching elements are predetermined as a function of control parameters of the electric motor.

Method for switching an operating state of an electric machine and device for switching an operating state of an electric machine

The invention relates to a method for jointly controlling asynchronous machines () of a motor vehicle () having a first asynchronous machine () and a second asynchronous machine () for driving the motor vehicle (); an inverter (), which is designed to supply the first asynchronous machine () and the second asynchronous machine () with a common stator voltage () at a common stator frequency (). The method comprises the steps of determining a specified setpoint drive torque () of the motor vehicle () for a current driving situation of the motor vehicle (); sensing a first rotational speed () of the first asynchronous machine () and a second rotational speed () of the second asynchronous machine (); determining a common operating strategy of the first asynchronous machine () and of the second asynchronous machine () according to the specified setpoint torque () while taking into account the sensed rotational speeds (); and controlling the stator voltage () and the stator frequency () in order to set the drive torques () of the asynchronous machines () according to the operating strategy.

Control device and method for jointly controlling asynchronous machines of a motor vehicle

The present invention provides a device and a method for changing the operating state of an electric machine to the free-wheeling mode, in which significant excessive increases in voltage can be avoided. In the freewheeling mode, the individual phase connections of an electric machine are disconnected electrically from one another in order to change the electric machine into a safe operating state. According to the invention, only some of the phase currents of the electric machine are evaluated. On the basis of the evaluated phase currents, suitable times for the disconnection of all the phase connections are determined, that is to say even for the phases in which no evaluation of the phase currents takes place.

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Stuttgart, Germany

Ekard Grossmann