Abstract: The invention relates to an electric machine (10), particularly a generator or a starter generator for a motor vehicle, comprising a converter (64) which is arranged on a cooling element (53) and composed of semiconductor switching elements (58, 59) actuated synchronously with the phase frequency for rectifying a generator alternating voltage or supplying a motor from a DC voltage source (61). According to the invention, the cooling element (53) has a base plate (55) and cooling fins (54), wherein the ratio of the surface wetted by coolant to the volume of the cooling element (53) ranges from 0.5 to 1.5 [l/mm], preferably from 0.8 to 1.0 [l/mm].

Abstract: A method is described for shutting off an internal combustion engine in a vehicle that comprises an internal combustion engine and an electrical machine, an electrical torque furnished by the electrical machine being adapted in such a way that a change per unit time in a total torque lies within a definable range, the total torque being made up at least of a torque of the internal combustion engine and the electrical torque.

Abstract: In a method for reducing the starting current of a multi-phase machine operated by block commutation, which includes a battery, one high side switch for each phase, a low side switch and a phase winding as well as a rotor, the high side switch assigned to one current phase or the low side switch assigned to one current phase is held in the closed state, and the low side switches or the high side switches assigned to the other current phases are alternately controlled.

Abstract: An electrical machine includes an angular position transducer for identifying a first rotation angle of a rotor; a stator winding for generating a magnetic field; a voltage measuring instrument for sensing a pole wheel voltage at the ends of the stator winding upon a rotation of the rotor; and an identification circuit for identifying a second rotation angle from the pole wheel voltage and for identifying an angle difference between the first and the second rotation angle.

Abstract: A method for reducing a ripple, caused by rotational nonuniformity of an internal combustion engine, in the output voltage of a generator which is driven by the internal combustion engine is provided. The generator has a stator winding, a rotor winding, a field controller, associated with the rotor winding, for regulating the output voltage of the generator, and a downstream power converter having controllable switching elements. To reduce the voltage ripple, the output voltage of the generator is regulated on the stator side by appropriately controlling the switching elements of the power converter.

Abstract: A method for operating an energy supply unit for a motor vehicle electrical system including at least one first subsystem and one second subsystem having different voltage levels, one first stator winding of an electric machine being connected via one first converter circuit to the first subsystem, and one second stator winding of the electric machine being connected via one second converter circuit to the second subsystem, and a DC-DC conversion taking place between the first subsystem and the second subsystem, while one of the converter circuits Is operated as an inverter and the other of the converter circuits is operated as a rectifier, and the first stator winding and the second stator winding are operated as a transformer.

Abstract: A method is described for controlling a multiphase machine which is connected to a battery, the multiphase machine having a DC link which is provided with a DC link capacitor, phase windings, and a high side switch and a low side switch for each phase. The switches associated with the individual phases are controlled by a control unit in such a way that sinusoidal phase currents are predefined, at least one phase current is connected at any point in time in each control cycle, and a fixed, pulsed control pattern is present for each control cycle. The control widths of the actuating signals associated with the phases are constant in the pulsed control pattern. The control pulses associated with the individual phases are predefined in such a way that the DC link current which arises is minimized.

Abstract: A method for reducing a ripple, caused by rotational nonuniformity of an internal combustion engine, in the output voltage of a generator which is driven by the internal combustion engine is provided. The generator has a stator winding, a rotor winding, a field controller, associated with the rotor winding, for regulating the output voltage of the generator, and a downstream power converter having controllable switching elements. To reduce the voltage ripple, the output voltage of the generator is regulated on the stator side by appropriately controlling the switching elements of the power converter.

Abstract: In a method for reducing the starting current of a multi-phase machine operated by block commutation, which includes a battery, one high side switch for each phase, a low side switch and a phase winding as well as a rotor, the high side switch assigned to one current phase or the low side switch assigned to one current phase is held in the closed state, and the low side switches or the high side switches assigned to the other current phases are alternately controlled.

Abstract: A method and a device for improving the restart of a vehicle equipped with start-stop operation. In order to accelerate the restart, in a stop phase of the start-stop operation a control unit provides control signals on the basis of which the excitation winding is supplied with a pre-excitation current in the stop phase. In addition, given the presence of a restart request occurring during the slowdown of the internal combustion engine, the control unit checks whether an immediate restart is possible and sensible, and, in the case in which an immediate restart is possible and sensible, initiates an immediate restart, and delays the restart in the case in which an immediate restart is not possible or not sensible.

Abstract: The invention relates to an electric machine (10), particularly a generator or a starter generator for a motor vehicle, comprising a converter (64) which is arranged on a cooling element (53) and composed of semiconductor switching elements (58, 59) actuated synchronously with the phase frequency for rectifying a generator alternating voltage or supplying a motor from a DC voltage source (61). According to the invention, the cooling element (53) has a base plate (55) and cooling fins (54), wherein the ratio of the surface wetted by coolant to the volume of the cooling element (53) ranges from 0.5 to 1.5 [l/mm], preferably from 0.8 to 1.0 [l/mm].