METHOD AND DEVICE FOR REGULATING AN ELECTRIC MACHINE

Abstract

The invention relates to a method (400) for regulating an electric machine (190) comprising a harmonic regulator (100), wherein the harmonic regulator comprises an input transformer (110), a regulator (120), and an output transformer (130). The method has the steps of: ascertaining (410) a feedback variable (Idq); transforming (420) the feedback variable (Idq); ascertaining (430) a regulating deviation; ascertaining (440) an equalization variable (UHrmc*); back-transforming (450) the equalization variable (UHrmc*); and energizing (480) at least one winding of the electric machine (190) on the basis of the actuating variable (UdqHrmc*).

Claims

1. A method (400) for controlling an electric machine (190) having a harmonic controller (100), the harmonic controller comprising an input transformer (110), a controller (120) and an output transformer (130), the method comprising the steps of: ascertaining (410) a feedback variable (Idq), the feedback variable comprising an actual variable of a harmonic of a specified frequency in a field-oriented system; transforming (420) the feedback variable (Idq) by means of the input transformer (110) to form a DC feedback variable (IHrmc) in a harmonic-oriented system; ascertaining (430) a control deviation as the difference between a DC reference variable (IHrmc*) and the DC feedback variable (IHrmc) in the harmonic-oriented system; ascertaining (440) a DC manipulated variable (UHrmc*) by means of the controller (120) as a function of the control deviation; back-transforming (450) the DC manipulated variable (UHrmc*) by means of the output transformer to form a manipulated variable (UdqHrmc*) in the field-oriented system; and energizing (480) at least one winding of the electric machine (190) as a function of the manipulated variable (UdqHrmc*).

2. The method as claimed in claim 1, wherein the feedback variable (Idq) in the field-oriented system comprises a harmonic with a positive frequency with a first amplitude and a first phase of a k.sup.th order of an electrical frequency of the electric machine (190) and/or a harmonic with a negative frequency with a second amplitude and a second phase of the k.sup.th order of an electrical frequency of the electric machine (190).

3. The method as claimed in claim 2, wherein transforming (420) the feedback variable (Idq) is performed as a function of an ascertained current rotor angle (w) of the electric machine (190), and transforming (420) comprises rotation with a rotation angle which corresponds to k times the current rotor angle (w).

4. The method as claimed in claim 1, wherein the DC reference variable (IHrmc*) of the harmonic-oriented system comprises a target value in the harmonic-oriented system for generating a harmonic on a sinusoidal phase current for energizing at least one winding of the electric machine (190).

5. The method as claimed in claim 1, wherein the DC manipulated variable (UHrmc*) is ascertained (440) by means of the controller (120) as a function of the control deviation by means of a control operation, using: a PI or I controller, an inverse static or dynamic model and a PI or I controller or a controller with an inverse static or dynamic model.

6. The method as claimed in claim 1, wherein the DC manipulated variable (UHrmc*) is back-transformed (450) as a function of an ascertained current rotor angle (w) of the electric machine (190), and back-transforming (450) comprises rotation with a rotation angle which corresponds to k times the current rotor angle (w), and back-transforming (450) respectively comprises rotation in the positive and/or negative opposite direction to the rotation of the feedback variable (Idq) by means of the input transformer (110).

7. The method as claimed in claim 1, having a fundamental controller (200), the fundamental controller comprising a fundamental input transformer (210), a fundamental controller (220) and a fundamental output transformer (230), further comprising the steps of: ascertaining (402) a machine feedback variable (Iabc), the machine feedback variable comprising an actual variable of the electric machine; transforming (404) the machine feedback variable (Iabc) by means of the fundamental input transformer (210) to form the feedback variable (Idq) in the field-oriented system; ascertaining (406) the fundamental control deviation as the difference between the specified fundamental DC reference variable (Idq*) and the feedback variable (Idq) in the field-oriented system; ascertaining (408) a fundamental DC manipulated variable by means of the fundamental controller (220) as a function of the fundamental control deviation; superimposing (460) the fundamental DC manipulated variable with the manipulated variable (UdqHrmc*); and back-transforming (470) the output variable of the superimposition by means of the fundamental output transformer (230) to form a machine manipulated variable (Uabc*), and energizing (480) at least one winding of the electric machine (190) as a function of the machine manipulated variable (Uabc*).

8. The method as claimed in claim 7, wherein the specifiable DC reference variable (Idq*) of the field-oriented system comprises a target variable for generating the fundamental of a sinusoidal phase current for energizing at least one winding of the electric machine (190).

9. (canceled)

10. A non-transitory, computer-readable medium comprising instructions that when executed by a computer, cause said computer to control an electric machine (190) having a harmonic controller (100), the harmonic controller comprising an input transformer (110), a controller (120) and an output transformer (130), by: ascertaining (410) a feedback variable (Idq), the feedback variable comprising an actual variable of a harmonic of a specified frequency in a field-oriented system; transforming (420) the feedback variable (Idq) by means of the input transformer (110) to form a DC feedback variable (IHrmc) in a harmonic-oriented system; ascertaining (430) a control deviation as the difference between a DC reference variable (IHrmc*) and the DC feedback variable (IHrmc) in the harmonic-oriented system; ascertaining (440) a DC manipulated variable (UHrmc*) by means of the controller (120) as a function of the control deviation; back-transforming (450) the DC manipulated variable (UHrmc*) by means of the output transformer to form a manipulated variable (UdqHrmc*) in the field-oriented system; and energizing (480) at least one winding of the electric machine (190) as a function of the manipulated variable (UdqHrmc*).

11. A device (300) for controlling an electric machine (190), comprising a computer unit (310) and a harmonic controller (100), the harmonic controller comprising an input transformer (110), a controller (120) and an output transformer (130), wherein the device is configured to ascertain (410) a feedback variable (Idq), the feedback variable comprising an actual variable of a harmonic of a specified frequency in a field-oriented system; transform (420) the feedback variable (Idq) by means of the input transformer (110) to form a DC feedback variable (IHrmc) in a harmonic-oriented system; ascertain (430) a control deviation as the difference between a DC reference variable (IHrmc*) and the DC feedback variable (IHrmc) in the harmonic-oriented system; ascertain (440) a DC manipulated variable (UHrmc*) by means of the controller (120) as a function of the control deviation; back-transform (450) the DC manipulated variable (UHrmc*) by means of the output transformer to form a manipulated variable (UdqHrmc*) in the field-oriented system; and energize (480) at least one winding of the electric machine (190) as a function of the manipulated variable (UdqHrmc*).

12. The device (300) as claimed in claim 11, comprising a fundamental controller (200), the fundamental controller comprising a fundamental input transformer (210), a fundamental controller (220) and a fundamental output transformer (230), wherein the device is configure to ascertain (402) a machine feedback variable (Iabc), the machine feedback variable comprising an actual variable of the electric machine; transform (404) the machine feedback variable (Iabc) by means of the fundamental input transformer (210) to form the feedback variable (Idq) in the field-oriented system; ascertain (406) the fundamental control deviation as the difference between the DC reference variable (Idq*) and the feedback variable (Idq) in the field-oriented system; ascertain (408) a fundamental DC manipulated variable by means of the fundamental controller (220) as a function of the fundamental control deviation; superimpose (460) the fundamental DC manipulated variable with the manipulated variable (UdqHrmc*); and back-transform (470) the output variable of the superimposition by means of the fundamental output transformer (230) to form a machine manipulated variable (Uabc*), and energize (480) at least one winding of the electric machine (190) as a function of the machine manipulated variable (Uabc*).

13. An electric drive system (500) comprising an electric machine (190) and a device (300) as claimed in claim 11.

14. A vehicle (600) comprising an electric drive system (500) as claimed in claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In the following text, the invention is to be described in greater detail on the basis of some figures, in which

[0055] FIG. 1 shows a diagrammatic control structure of a harmonic controller

[0056] FIG. 2 shows a diagrammatic control structure for controlling an electric machine

[0057] FIG. 3 shows a diagrammatically illustrated flowchart for a method for controlling an electric machine

[0058] FIG. 4 shows a diagrammatically illustrated device for controlling an electric machine

[0059] FIG. 5 shows a diagrammatically illustrated vehicle comprising an electric drive system

DETAILED DESCRIPTION

[0060] FIG. 1 shows a schematic control structure of a harmonic controller 100, the harmonic controller 100 comprising an input transformer 110, a controller 120 and an output transformer 130. An ascertained feedback variable Idq in a field-oriented system is transformed by means of the input transformer 110 to form a DC feedback variable IHrmc in a harmonic-oriented system. An ascertained difference between a specifiable DC reference variable IHrmc* and the DC feedback variable IHrmc in the harmonic-oriented system is supplied to the controller 120 as the control deviation and the input variable. A DC manipulated variable UHrmc* is ascertained by means of the controller 120 as a function of the control deviation. This DC manipulated variable UHrmc* in the harmonic-oriented system is transformed by means of the output transformer 130 to form a manipulated variable UdqHrmc* in the field-oriented system. At least one winding of an electric machine 190 is preferably energized as a function of the manipulated variable UdqHrmc*.

[0061] FIG. 2 shows a diagrammatic control structure for controlling an electric machine 190. The electric machine 190 is illustrated as a unit comprising an inverter 192 and an electric motor 194. The fundamental controller 200 comprises a fundamental input transformer 210, a fundamental controller 220 and a fundamental output transformer 230. A machine feedback variable Iabc of the electric machine is ascertained in the time domain and supplied to the fundamental input transformer 210. The machine feedback variable Iabc is transformed by means of the fundamental input transformer 210 to form the feedback variable Idq in the field-oriented system. A fundamental control deviation is ascertained as the difference between a specifiable fundamental DC reference variable Idq* and the feedback variable Idq in the field-oriented system. A fundamental DC manipulated variable is ascertained by means of the fundamental controller 220 as a function of the fundamental control deviation. As illustrated in FIG. 1, the manipulated variable UdqHrmc* is ascertained in parallel by means of the harmonic controller 100. The fundamental DC manipulated variable is superimposed with the manipulated variable UdqHrmc*. The output variable of the superimposition in the field-oriented system is transformed by means of the fundamental output transformer 230 to form a machine manipulated variable Uabc* in the time domain. For the purpose of energizing at least one winding of the electric machine 190, the machine manipulated variable Uabc*, preferably a phase voltage, is supplied to said winding. The phase voltage is generated by means of the inverter 192 and applied at least to one winding of the electric motor 194.

[0062] FIG. 3 shows a diagrammatically illustrated flowchart of a method 400 for controlling an electric machine 190. The method starts with step 401. In step 402, a machine feedback variable Iabc of the electric machine is preferably ascertained in the time domain. In step 404, this machine feedback variable Iabc is preferably transformed by means of the fundamental input transformer 210 to form the feedback variable Idq in the field-oriented system. In step 406, a fundamental control deviation is preferably ascertained as the difference between a specifiable fundamental DC reference variable Idq* and the feedback variable Idq in the field-oriented system. In step 408, a fundamental DC manipulated variable is preferably ascertained by means of the fundamental controller 220 as a function of the fundamental control deviation.

[0063] In step 410, a feedback variable Idq is ascertained and in step 420 is transformed by means of the input transformer 110 to form a DC feedback variable IHrmc in a harmonic-oriented system. In step 430, a difference between a specifiable DC reference variable IHrmc* and the DC feedback variable IHrmc is supplied to the controller 120 as the control deviation and the input variable. In step 440, a DC manipulated variable UHrmc* is ascertained by means of the controller as a function of the control deviation. In step 450, this DC manipulated variable UHrmc* in the harmonic-oriented system is transformed by means of the output transformer to form a manipulated variable UdqHrmc* in the field-oriented system. In step 480, at least one winding of an electric machine 190 is preferably energized as a function of the manipulated variable UdqHrmc*.

[0064] In step 460, the fundamental DC manipulated variable is preferably superimposed with the manipulated variable UdqHrmc*. In step 470, the output variable of the superimposition in the field-oriented system is preferably transformed by means of the fundamental output transformer 230 to form a machine manipulated variable Uabc* in the time domain. In step 480, at least one winding of the electric machine 190 is preferably energized as a function of the machine manipulated variable Uabc*. The method ends with step 490.

[0065] FIG. 4 shows a diagrammatically illustrated device 300 for controlling an electric machine 190. The electric machine 190 is illustrated as a unit comprising an inverter 192 and an electric motor 194. The device 300 comprises a harmonic controller 100 and a computer unit 310 for controlling and implementing the structure of the harmonic controller 100. The device preferably comprises a fundamental controller 200, which is likewise controlled and implemented by means of the computer unit 310. The device is designed to execute the above-described method steps and therefore to operate and to control the electric machine 190.

[0066] FIG. 5 shows a diagrammatically illustrated vehicle 600 which comprises an electric drive system 500. The drive system 500 comprises the electric machine 190, which comprises an inverter 192 and an electric motor 194, and a device 300 for controlling the electric machine, as described in FIG. 4. The electric drive system preferably comprises a battery for supplying electrical power to the electric drive system 500.