METHOD AND DEVICE FOR OPERATING AN ELECTRIC MACHINE HAVING EXTERNAL OR HYBRID EXCITATION

• US 20130293182A1
• Filed: 11/22/2011
• Published: 11/07/2013
• Est. Priority Date: 12/27/2010
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Neuburger, Martin, Reutlinger, Kurt
• Granted Patent: US 10,622,859 B2
• Time in Patent Office: Days
• US Class Current: 318/716
• CPC Class Codes: H02K 3/28 Layout of windings or of connections between windings windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32
• CPC Class Codes: H02M 1/009 having two or more independently controlled outputs for DC-DC converter with intermediate AC H02M3/33561
• CPC Class Codes: H02P 25/024 controlled by supply frequency
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: H02P 6/10 Arrangements for controlling torque ripple, e.g. providing reduced torque ripple

Abstract

The invention relates to an electronically commutated electric machine (2) comprising: a rotor (21); an exciting winding (6) that is located at the rotor (21) in order to generate or alter a direct magnetic field in the rotor (21); a stator (22) comprising a three- or multi-phase stator winding (23) with phases that can be controlled via phase lines (8). The exciting winding (6) is connected to the stator winding (23).

Claims

1. An electronically commutated electric machine (2), comprising:

a rotor (21);

an exciter winding (6) arranged at the rotor (21) in order to generate or alter a direct magnetic field in the rotor (21); and

a stator (22) having a three-phase or polyphase stator winding (23) with phases which can be driven via phase lines (8);

wherein the exciter winding (6) is electrically connected to the stator winding (23).

2. The electric machine (2) as claimed in claim 1, wherein the exciter winding (6) is connected to a supply potential via an exciter winding line (11).

3. The electric machine (2) as claimed in claim 1, wherein the exciter winding (6) is connected to one of the phase lines (8).

4. The electric machine (2) as claimed in claim 1, wherein the stator winding (23) has stator coils interconnected in star connection, wherein the exciter winding (6) is connected to a star point of the star connection.

5. A motor system (1) comprising:

an electric machine (2) as claimed in claim 3;

a power stage (3) for providing phase voltages and/or phase currents on the phase lines (8);

a control unit (5) for driving the power stage, such that the phase line (8) connected to the exciter winding (6) has a constant phase potential and such that the remaining phase voltages are provided in such a way that in each case sinusoidal voltage profiles arise as differential voltages between the phase lines (8).

6. A motor system (1) comprising:

an electric machine (2) as claimed in claim 4;

a power stage (3) for providing phase voltages and/or phase currents on the phase lines (8);

a control unit (5) for driving the power stage (3), such that phase voltages have in each case sinusoidal voltage profiles that are phase-offset with respect to one another.

7. The motor system (1) as claimed in claim 6, wherein the control unit (5) is designed to generate the phase voltages with the aid of a pulse width modulation by varying duty ratios of the pulse width modulation for generating the phase voltages, and to set a current through the exciter winding by applying a duty ratio offset to the duty ratios for all the phase voltages.

8. Method for operating an electric machine (2) as claimed in claim 3, wherein a constant phase potential is applied to the phase line (8) connected to the exciter winding (6), and wherein the remaining phase voltages are provided in such a way that in each case sinusoidal voltage profiles arise as differential voltages between the phase lines (8).

9. A method for operating an electric machine (2) as claimed in claim 4, wherein the power stage (3) is driven in such a way that phase voltages have in each case sinusoidal voltage profiles that are phase-offset with respect to one another.

10. The method as claimed in claim 9, wherein the phase voltages are generated with the aid of a pulse width modulation by the variation of duty ratios of the pulse width modulation for generating the phase voltages, and wherein a current through the exciter winding (6) is set by a duty ratio offset being applied to the duty ratios for all the phase voltages.

11. The electric machine (2) as claimed in claim 2, wherein the exciter winding line (11) is connected to an electrically conductive housing of the electric machine (2).