Electric machine in a motor vehicle having a rotational speed signal input
A method for operating an electric machine coupled to an internal combustion engine in a motor vehicle, the electric machine having a stator winding, a rotor winding, a field regulator assigned to the rotor winding and a current converter post-connected to the stator winding having controllable switching elements, in which during a starting process of the internal combustion engine the electric machine is operated as a motor according to a rotational speed specification signal.
1. A method for operating an electric machine coupled to an internal combustion engine in a motor vehicle, the method comprising:
operating, during a starting process of the internal combustion engine, the electric machine as a motor according to a rotational speed specification signal;
wherein the electric machine includes a stator winding, a rotor winding, a field regulator assigned to the rotor winding and a current converter post-connected to the stator winding having controllable switching elements.
2. The method of claim 1 , wherein the rotational speed specification signal includes a target rotational speed signal, and wherein the actual rotational speed of the electric machine is regulated to a target rotational speed specified by the target rotational speed signal.
3. The method of claim 2 , wherein the regulation of the actual rotational speed of the electric machine to the target rotational speed specified by the target rotational speed signal is terminated when a rotational speed of the internal combustion engine reaches a rotational speed stability threshold.
4. The method of claim 1 , wherein the rotational speed specification signal includes a lower rotational speed threshold signal, and wherein the electric machine is operated as a motor only when a rotational speed of the electric machine reaches a lower rotational speed threshold specified by the lower rotational speed threshold signal.
5. The method of claim 4 , wherein the internal combustion engine is turned on by a starter that is different from the electric machine.
6. The method of claim 5 , wherein turning on the electric machine takes place while taking into account a latency.
7. The method of claim 1 , wherein the rotational speed specification signal includes a selection signal, so as to select a specified rotational speed curve or a torque curve to be followed by the electric machine.
8. The method of claim 1 , wherein the operation as a motor of the electric machine is terminated when a rotational speed of the internal combustion engine reaches a rotational speed stability threshold.
9. The method of claim 1 , wherein a starter-generator or a boost-recuperation machine is operated as the electric machine.
10. An arithmetic unit for operating an electric machine coupled to an internal combustion engine in a motor vehicle, comprising:
an arithmetic arrangement which is configured to operate, during a starting process of the internal combustion engine, the electric machine as a motor according to a rotational speed specification signal;
wherein the electric machine includes a stator winding, a rotor winding, a field regulator assigned to the rotor winding and a current converter post-connected to the stator winding having controllable switching elements.
11. A non-transitory computer readable medium having a computer program, which is executable by a processor, comprising:
a program code for operating an electric machine coupled to an internal combustion engine in a motor vehicle, by operating, during a starting process of the internal combustion engine, the electric machine as a motor according to a rotational speed specification signal;
wherein the electric machine includes a stator winding, a rotor winding, a field regulator assigned to the rotor winding and a current converter post-connected to the stator winding having controllable switching elements.
12. The non-transitory computer readable medium of claim 11 , wherein the rotational speed specification signal includes a target rotational speed signal, and wherein the actual rotational speed of the electric machine is regulated to a target rotational speed specified by the target rotational speed signal.
13. An electric machine for use in a motor vehicle for coupling to an internal combustion engine, comprising:
a stator winding;
a rotor winding;
a field regulator assigned to the rotor winding; and
a current converter, which is post-connected to the stator winding, having controllable switching elements and an arithmetic unit;
wherein the arithmetic unit includes an arithmetic arrangement being configured to operate, during a starting process of the internal combustion engine, the electric machine as a motor according to a rotational speed specification signal.
14. The electric machine of claim 13 , further comprising:
an input for receiving the rotational speed specification signal.
15. A vehicle electrical system of a motor vehicle, comprising:
an engine control unit to control the internal combustion engine and to output a rotational speed specification signal; and
an electric machine for use in a motor vehicle for coupling to an internal combustion engine, including:
a stator winding;
a rotor winding;
a field regulator assigned to the rotor winding; and
a current converter, which is post-connected to the stator winding, having controllable switching elements and an arithmetic unit;
wherein the arithmetic unit includes an arithmetic arrangement being configured to operate, during a starting process of the internal combustion engine, the electric machine as a motor according to a rotational speed specification signal.