Method and apparatus for regulating an electric machine

Abstract

A method (400) for regulating an electric machine (190) with a harmonic regulator (100), wherein the harmonic regulator comprises an input transformation (110), a regulator (120) and an output transformation (130), the method having the steps of determining (410) a feedback variable (Idq), transforming (420) the feedback variable (Idq), determining (430) a regulation deviation, determining (440) a constant manipulated variable (UHrmc*), inverse transforming (450) the constant manipulated variable (UHrmc*), energizing (480) at least one winding of the electric machine (190) as a function of the manipulated variable (UdqHrmc*).

Description

TECHNICAL FIELD

[0001] The present application relates to a method and a device for regulating an electric machine. The present application also relates to an electric drive system having a corresponding device and a vehicle having an electric drive system as well as a computer program and a computer-readable storage medium. BACKGROUND

[0002] The publication DE 2017 102 03691 A1 discloses a regulation for an electric machine, in the case of which interference quantities are simultaneously compensated and target values are set. For the operation of the electric machine, a phase current is adjusted as a target value. The phase current is preferably adjusted to be a sinusoidal fundamental wave. In the operation of the electric machine, the phase current causes an output of a uniform average torque. Due to non-ideal sinusoidal magnetic fields, winding arrangements, slotting, tooth shapes, saturation effects and / or other effects, in addition to the uniform average torque, also harmonics of the torque are formed. This effect leads to force waves between the rotor and the stator, which act as tangential and radial tooth forces on the stator teeth in the case of characteristic orders. Due to the mechanical transfer behavior of the electric machine, these forces can be perceived as vibrations in the machine, the machine housing and the coupling elements and thereby as structure and air-borne noise or surface vibrations. Here, the harmonics of the torque also cause harmonics of the electric frequency of the electric machine on the phase current as interference quantities. In order to minimize these interference quantities, harmonics are purposefully adjusted and specified, which are superimposed to the adjusted and specified phase current.

[0003] There is a need for alternative methods and devices for regulating an electric machine with which harmonics are adjusted as robustly, stably, dynamically and flexibly as possible in order to take into account important frequency components. SUMMARY

[0004] A method for regulating an electric machine with a harmonic regulator is provided, wherein the harmonic regulator comprises an input transformation, a regulator and an output transformation. The method comprises the following steps:

[0005] determining a feedback variable, wherein the feedback variable comprises an actual variable of a harmonic of a specified frequency in a field-oriented system;

[0006] transforming the feedback variable into a constant feedback variable in a harmonic-oriented system by means of the input transformation;

[0007] determining a regulation deviation as a difference between a specifiable constant control variable and the constant feedback variable in the harmonic-oriented system;

[0008] determining a constant manipulated variable from the regulation deviation by means of the regulator;

[0009] transforming the constant manipulated variable into a manipulated variable in the field-oriented system by means of the output transformation;

[0010] determining a constant manipulated variable from the control deviation.

[0011] For the regulation of electrical machines, field-oriented regulation is widely used. Here, alternating variables, also called fundamental waves, of the phase currents to be regulated, which are preferably sinusoidal in the time domain, are transferred into a coordinate system rotating with the frequency of these alternating variables, respectively, by means of a mathematical transformation. The frequency of these alternating variables also determines the frequency of the magnetic field in the machine, so that this coordinate system rotating with the frequency of the alternating variables is also called the field-oriented system. In the steady-state operation of the electrical machine, constant variables in the field-oriented system result from the alternating variables in the time domain, which can be regulated by means of usual methods of regulation technology. The field-oriented system is also called the d / q coordinate system. Here, the d-axis of the d / q coordinate system points in the direction of the rotor flux. The q-axis is perpendicular to the d-axis. The sinusoidal phase currents are represented as stator current vectors or stator current vectors, which are characterized by their length and their direction. The current vectors rotate synchronously with the rotating stator or rotor flux of the electrical machine. In the d / q coordinate system, the current vectors can be represented by means of two mutually perpendicular components Idand Idaccording to their length and their direction, which are both constant variables in the steady-state case.

[0012] For the regulation of electrical machines, which can be connected or can be connected to a harmonic regulator, feedback variables of the electrical machine are recorded in the field-oriented system. The feedback variables include harmonics, which are superimposed on the phase currents through the electrical machine. In the field-oriented system, the phase currents are constant variables, while the harmonics are alternating variables. Thus, for the regulation of the harmonics, a further mathematical transformation from the field-oriented system to a harmonic-oriented system with the frequency of the harmonics is similar to the transformation from the time domain to the field-oriented domain. For this purpose, the feedback variables are transformed into the harmonic-oriented system by means of an input transformation to constant feedback variables. In the steady-state operation of the electrical machine, variables which are represented as alternating variables in the field-oriented system are represented as constant variables in the harmonic-oriented system. These constant variables can be regulated by means of usual methods of regulation technology. Correspondingly, a control deviation is determined as the difference between the assignable constant control variables and the constant feedback variables in the harmonic-oriented system. By means of the regulator, a constant manipulated variable is determined from the control deviation. This constant manipulated variable, which is a constant variable in the harmonic-oriented system, is inversely transformed into a manipulated variable in the field-oriented system by means of an output transformation for further use in the field-oriented regulation of the electrical machine. In the field-oriented system, the manipulated variable includes alternating variables, i.e. harmonics. Finally, the method includes the step of energizing the electrical machine from the manipulated variable.

[0013] Advantageously, a method for an efficient harmonic regulator is provided.

[0014] Within the scope of the present application, the expression that the variable of the regulating loop comprises a harmonic or a fundamental means that the variable of the regulating loop characterizes or describes at least one harmonic or a fundamental, wherein the respective variable of the regulating loop can also contain further signal components, for example the fundamental and one or more harmonics and additionally also present disturbing quantities.

[0015] For the regulation of the electrical machine, the target phase currents are generally specified in accordance with the torque specification from the determined actual phase currents, wherein the phase voltages are set as manipulated variables. Therefore, preferably within the scope of the present application, the feedback variable (Idq), the constant feedback variable (IHrmc), the constant control variable (IHrmc*), the machine feedback variable (Iabc) or the assignable GW constant control variable (Idq*) respectively comprises a current value; and / or the constant manipulated variable (UHrmc*), the manipulated variable (UdqHrmc*), the GW constant manipulated variable or the machine manipulated variable (Uabc*) respectively comprises a voltage value.

[0016] In another design of the application, the feedback variable in the field-oriented system comprises a harmonic of the k-th order of the electrical frequency of the electrical machine with a first amplitude and a first phase with positive frequency and / or a harmonic of the k-th order of the electrical frequency of the electrical machine with a second amplitude and a second phase with negative frequency.

[0017] The feedback variable in the field-oriented system comprises at least one harmonic. With respect to the electrical frequency of the electrical machine, the harmonic or the harmonics have a positive and / or negative frequency of the k-th order with a respective amplitude and phase. The order which represents an important disturbing quantity due to its amplitude in particular being particularly large is for example the 6th order, preferably in the positive and negative direction. For example in the case of an electrical frequency of the electrical machine, i.e. a fundamental, of 450 Hz, the 6th order frequency is 450 Hz + 450 Hz * 6 = 3150 Hz and in the negative direction 450 Hz - 6 * 450 Hz = -2250 Hz. In the field-oriented system whose coordinate system rotates with the electrical frequency of the electrical machine, the electrical frequency of the electrical machine is mapped to 0 Hz and for the + / - 6th order harmonics frequencies of +2700 Hz and -2700 Hz result. Depending on the size of the amplitude and the phase, force waves between the rotor and the stator of the electrical machine result which act as tangential and radial tooth forces on the stator teeth and cause harmonic oscillations of the torque. The more important solutions of the feedback variable are taken into account for the regulation, the more effectively the disturbing quantities are eliminated.

[0018] Advantageously, a feedback variable for an effective harmonic regulation is provided.

[0019] In another design of the application, the feedback variable is transformed in accordance with a determined current rotor angle of the electrical machine and the transformation comprises a rotation by a rotation angle which corresponds to k times the current rotor angle. Here, the rotation is carried out in the positive and / or negative direction.

[0020] The transformation from the field-oriented system to the harmonic-oriented system comprises a rotation by means of a rotation matrix or a rotation matrix. Thus, the alternating variables in the field-oriented system become constant variables in the harmonic-oriented system. For this purpose, the feedback variables are rotated by a rotation angle corresponding to k times the current rotor angle, i.e. in the case of a transformation of the 6th harmonic of the electrical frequency by 6 times the current rotor angle. For k harmonics in the positive direction, the rotation is in the positive direction, in the case of k harmonics in the negative direction, the rotation is in the negative direction. The resulting constant variables in the harmonic-oriented system can be specified, characterized or described by means of complex numbers or as complex parameters, for example as iPosReal, iPosImag or as iNegReal and iNegImag.

[0021] In addition to the rotation, alternatively, other transformations can also be used. For example, the complex components iQSin, IQCos (also referred to as mixing or heterodyning) can also be calculated by multiplying the d current by a sine depending on the k times the rotor angle and by a cosine of the complex component iDSin, IDCos and by multiplying the q current by the sine and by the cosine.

[0022] As a further alternative, complex harmonics can be used which have the amplitude and the phase of the d current and the q current, respectively.

[0023] Again, these components can also be presented as ellipses with height, width, rotation and phase by means of the superposition of two counter-rotating vectors with different amplitudes and phases, preferably for particularly efficient calibration.

[0024] Advantageously, a transformation is provided to provide constant variables which enable an efficient harmonic regulation.

[0025] In a further design of the application, the assignable constant control variables of the harmonic-oriented system comprise target variables in the harmonic-oriented system for generating harmonics on the sinusoidal phase current to energize at least one winding of the electrical machine.

[0026] The constant control variables are target values for generating harmonics of an assignable frequency or of k order to superimpose the sinusoidal phase current or the fundamental wave to energize the electrical machine. The target values are specified analytically, in particular, from a torque specification, a (phase) current target value or an actual current value, a determined (phase) current target value or actual current value of the phase current or by means of a synthesis characteristic curve. For use in the harmonic regulator in the harmonic-oriented system, the target values have been correspondingly specified transformed.

[0027] Advantageously, constant control variables are provided for an efficient harmonic regulation.

[0028] In another design of the application, the constant manipulated variable is determined by means of the regulator according to the regulation deviation by means of a regulation using a PI or I regulator, an inverse static or dynamic model and a PI or I regulator or a regulator with an inverse static or dynamic model.

[0029] In the case of a PI or I regulator, a separate, mutually separate regulator is used for each harmonic current component, i.e. for example iPosReal, iPosImag, iNegReal and / or iNegImag.

[0030] In the case of an inverse static or dynamic model and a PI or I regulator, the regulation deviation or current deviation is converted into a voltage deviation with the inverse model. Then, a separate, mutually separate PI or I regulator is used for each harmonic voltage component, i.e. for example uPosReal, uPosImag, uNegReal and / or uNegImag. The model is calculated according to the d / q model or field-oriented model of the electric machine. The model can be designed to be static or can also take dynamic components into account. The regulation using a model taking dynamic components into account is more precise and allows a higher regulator dynamics.

[0031] In the case of a regulator with an inverse model (known as IMC regulator (internal model control)) or a CVD regulator (complex vector design), the inverse regulator corresponds to the inverse model of the controlled system function multiplied by an integrator. For the closed regulation loop T, the following applies:

[0032]

[0033]

[0034]

[0035] where the variables represent the following parameters:

[0036] G: machine model

[0037] K: regulator model

[0038] T: closed regulation loop

[0039] : bandwidth

[0040] s: Laplace.

[0041] Here, the individual components, for example iPosReal, iPosImag, iNegReal and iNegImag, are no longer adjusted separately. Only the limit frequency is specified which specifies the desired low-pass behavior of the closed control loop.

[0042] Since in the case of this regulator the closed control loop results in a low-pass behavior, a further low-pass in the control loop is not reasonable. Even in this variant, the control using a model which takes into account the dynamic components is more precise.

[0043] Advantageously, different regulators are provided for an efficient harmonic control.

[0044] In another design of the application, the constant manipulated variable is inversely transformed depending on the determined current rotor angle of the electrical machine. The inverse transformation comprises a rotation by a rotation angle which corresponds to k times the current rotor angle. The inverse transformation comprises a rotation in the positive and / or the opposite negative direction of the rotation of the feedback variable by means of the input transformation, respectively.

[0045] The transformation from the harmonic-oriented system to the field-oriented system comprises a rotation by means of a rotation matrix or a rotation matrix. In this way, the constant variable in the harmonic-oriented system becomes an alternating variable in the field-oriented system. For this purpose, the constant manipulated variable is rotated by a rotation angle which corresponds to k times the current rotor angle, i.e. in the case of a transformation of the 6th harmonic of the electrical frequency by 6 times the current rotor angle. For the kth harmonic in the positive direction, a rotation in the positive direction takes place, in the case of the kth harmonic in the negative direction, a rotation in the negative direction takes place. Preferably, in the case of the rotation in the negative and positive direction, the resulting alternating variables in the field-oriented system are added to the manipulated variable in a complex manner.

[0046] In addition to the rotation, alternatively, other transformations, as described above, can also be used.

[0047] Advantageously, the inverse transformation is provided in order to provide alternating variables which can be further used for an efficient fundamental control.

[0048] In another design of the method for controlling an electrical machine, the electrical machine further comprises a fundamental control, wherein the fundamental control comprises a GW input transformation, a GW controller and a GW output transformation. The method comprises the following further steps:

[0049] determining a machine feedback variable, wherein the machine feedback variable comprises actual variables of the electrical machine;

[0050] transforming the machine feedback variable into a feedback variable in a field-oriented system by means of the GW input transformation;

[0051] determining a GW constant control deviation as a difference between a specifiable GW constant control variable and the feedback variable in the field-oriented system;

[0052] determining a GW constant manipulated variable from the GW constant control deviation by means of a GW regulator;

[0053] superimposing the GW constant manipulated variable on the manipulated variable;

[0054] inverting the superimposed output variable into a machine manipulated variable in the time domain by means of a GW output transformation; and energizing at least one winding of the electrical machine in accordance with the machine manipulated variable.

[0055] In addition to the harmonic regulation, the regulation comprises fundamental regulation. By means of the fundamental regulation, an alternating variable of a desired adjusted phase current, which is preferably sinusoidal in the time domain, is regulated. For regulating the electrical machine, which can be connected to or can be connected to a fundamental regulator, a machine feedback variable, i.e. an actual variable, of the electrical machine is recorded in the time domain. The machine feedback variable is preferably the phase current of the electrical machine. The machine feedback variable comprises the phase current as a fundamental and comprises harmonics as disturbing quantities, which are superimposed on the phase current through the electrical machine. In the time domain, the phase current is an alternating variable, which is superimposed on other alternating variables of the harmonics. For regulating the fundamental, a transformation from the time domain into the field-oriented domain takes place. For this purpose, the machine feedback variable is transformed into a feedback variable in the field-oriented system by means of a GW input transformation. Preferably, within the scope of the present application, "GW" as a symbol stands for the regulation steps and transformations which are used for regulating the fundamental. In the steady-state operation of the electrical machine, the alternating variables in the time domain result in constant variables in the field-oriented system. These constant variables can be regulated by means of usual methods of regulation technology. Correspondingly, a GW constant control deviation is determined as a difference between a specifiable GW constant control variable and the feedback variable in the field-oriented system. By means of a GW regulator, a GW constant manipulated variable is determined from the GW constant control deviation. This manipulated variable is superimposed or added to the GW constant manipulated variable in the field-oriented system as an output signal of the harmonic regulator. The superimposed output variable in the field-oriented system is inverted into a machine manipulated variable in the time domain by means of a GW output transformation for further use for the purpose of the machine being manipulated or energized in the time domain. In the time domain, the machine manipulated variable comprises an alternating variable, i.e. the fundamental, and at least one other superimposed alternating variable, i.e. the harmonics. Finally, the method comprises the step of energizing the electrical machine in accordance with the machine manipulated variable.

[0056] Advantageously, a method for an efficient fundamental and harmonic regulator is provided.

[0057] In another design of the application, the specifiable GW constant control variable of the field-oriented system comprises a target variable for generating a fundamental of a sinusoidal phase current for energizing at least one winding of the electrical machine.

[0058] The GW constant control variable is a target value for generating a fundamental wave having an electrical frequency of the electrical machine for energizing the electrical machine. This target value is specified, in particular, analytically from a torque specification, a (phase) current target value or an actual current value, preferably a (phase) current target value or an actual current value of the determined phase current, or by means of a synthesis characteristic curve. For use in a GW regulator in a field-oriented system, this target value has been correspondingly transformed for specification.

[0059] Advantageously, a GW constant control variable is provided for an efficient fundamental wave regulation.

[0060] The present application also relates to a computer program comprising instructions which, when executed by a computer, cause the computer to carry out the steps of the method described so far.

[0061] The present application also relates to a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the steps of the method described so far.

[0062] The present application also relates to a device for regulating an electrical machine, having a computing unit and a harmonic regulator, wherein the harmonic regulator comprises an input transformation, a regulator and an output transformation. The device is set up to carry out the steps of the described method.

[0063] Advantageously, a device for an efficient harmonic regulation of an electrical machine is provided.

[0064] In another design variant of the present application, the device comprises a fundamental wave regulator, wherein the fundamental wave regulator comprises a GW input transformation, a GW regulator and a GW output transformation. The device is set up to carry out the steps of the described method.

[0065] Advantageously, a device for an efficient combined fundamental wave and harmonic regulation of an electrical machine is provided.

[0066] The present application also relates to an electric drive system having an electrical machine and the described device. Such an electric drive system is used, for example, for driving an electric vehicle. An optimized operation of the drive train can be achieved by means of the method and the device.

[0067] The present application also relates to a vehicle having the described drive system. Advantageously, a vehicle is thus provided which comprises a device for an efficient regulation of an electrical machine.

[0068] It is easily understood that the features, characteristics and advantages of the method according to the present application can be applied or adapted accordingly to the device or the drive system and the vehicle, and vice versa.

[0069] Further features and advantages of embodiments of the present application will become apparent from the following description, taken in connection with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0070] In the following, the application shall be further explained with the aid of several drawings, for which purpose:

[0071] Figure 1 A schematic regulation structure of a harmonic regulator is shown;

[0072] Figure 2 A schematic regulation structure for regulating an electric machine is shown;

[0073] Figure 3 A flow chart of a method for regulating an electric machine is shown in a schematic representation;

[0074] Figure 4 An apparatus for regulating an electric machine is shown in a schematic representation;

[0075] Figure 5 A vehicle with an electric drive system is shown in a schematic representation. DETAILED DESCRIPTION

[0076] Figure 1 A schematic regulation structure of a harmonic regulator 100 is shown, wherein the harmonic regulator 100 comprises an input transformation 110, a regulator 120 and an output transformation 130. The determined feedback variable Idq in a field-oriented system is transformed into a constant feedback variable IHrmc in a harmonic-oriented system by means of the input transformation 110. The difference between the determined assignable constant control variable IHrmc* and the constant feedback variable IHrmc in the harmonic-oriented system is delivered as a regulation deviation and input variable to the regulator 120. By means of the regulator 120, a constant control variable UHrmc* is determined as a function of the regulation deviation. The constant control variable UHrmc* in the harmonic-oriented system is transformed into a control variable UdqHrmc* in the field-oriented system by means of the output transformation 130. Preferably, at least one winding of an electric machine 190 is energized as a function of the control variable UdqHrmc*.

[0077] Figure 2A schematic regulating structure for regulating an electric machine 190 is shown. The electric machine 190 is presented as a unit consisting of an inverter 192 and an electric motor 194. A fundamental wave regulator 200 comprises a GW input transformation 210, a GW regulating deviation 220 and a GW output transformation 230. Machine feedback variables Iabc of the electric machine are determined in the time domain and are delivered to the GW input transformation 210. The machine feedback variables Iabc are transformed into a field oriented system by means of the GW input transformation 210 to feedback variables Idq. A GW regulating deviation is determined as a difference between a specifiable GW constant control variable Idq* and the feedback variables (Idq) in the field oriented system. By means of the GW regulating deviation, a GW constant manipulated variable is determined according to the GW regulating deviation. As Figure 1 shown in Fig. 1, in parallel a manipulated variable UdqHrmc* is determined by means of the harmonic regulator 100. The GW constant manipulated variable is superimposed with the manipulated variable UdqHrmc*. The superimposed output variable in the field oriented system is transformed into the time domain by means of the GW output transformation 230 to machine manipulated variables Uabc*. In order to energize at least one winding of the electric machine 190, the machine manipulated variables Uabc*, preferably phase voltages, are supplied to the winding. The phase voltages are generated by means of the inverter 192 and are applied at least on the windings of the electric motor 194.

[0078] Figure 3 A flow chart of a schematically presented method 400 for regulating an electric machine 190 is shown. The method starts in step 401. Preferably, in step 402 machine feedback variables Iabc of the electric machine are determined in the time domain. Preferably, in step 404 the machine feedback variables Iabc are transformed into a field oriented system by means of a GW input transformation 210 to feedback variables Idq. Preferably, in step 406 a GW regulating deviation is determined as a difference between a specifiable GW constant control variable Idq* and the feedback variables (Idq) in the field oriented system. Preferably, in step 408 a GW constant manipulated variable is determined according to the GW regulating deviation by means of a GW regulating deviation.

[0079] The feedback variable Idq is determined in step 410 and transformed into the harmonic-oriented system in step 420 by means of the input transformation 110 to the constant feedback variable IHrmc. In step 430, the difference between the assignable constant control variable IHrmc* and the constant feedback variable IHrmc is delivered as an adjustment deviation and input variable to the regulator 120. In step 440, the constant control variable UHrmc* is determined from the adjustment deviation by means of the regulator. In step 450, the constant control variable UHrmc* in the harmonic-oriented system is transformed into the control variable UdqHrmc* in the field-oriented system by means of the output transformation. Preferably, in step 480, at least one winding of the electric machine 190 is energized in accordance with the control variable UdqHrmc*.

[0080] Preferably, in step 460, the GW constant control variable is superimposed on the control variable UdqHrmc*. Preferably, in step 470, the superimposed output variable in the field-oriented system is transformed into the time domain by means of the GW output transformation 230 to the machine control variable Uabc*. Preferably, in step 480, at least one winding of the electric machine 190 is energized in accordance with the machine control variable Uabc*. The method ends with step 490.

[0081] Figure 4 A schematically presented device 300 for adjusting an electric machine 190 is shown. The electric machine 190 is presented as a unit consisting of an inverter 192 and an electric motor 194. The device 300 comprises a harmonic regulator 100 and a computing unit 310 for controlling and implementing the structure of the harmonic regulator 100. The device preferably comprises a fundamental regulator 200, which is likewise controlled and implemented by means of the computing unit 310. The device is set up to carry out the above-described method steps and thus to operate and adjust the electric machine 190.

[0082] Figure 5 A schematically presented vehicle 600 is shown, which comprises an electric drive system 500. The drive system 500 comprises an electric machine 190, which comprises an inverter 192 and an electric motor 194, and a device 300 for adjusting the electric machine, as described in Figure 4 Preferably, the electric drive system comprises a battery for supplying the electric drive system 500 with electrical energy.

Claims

1. A method (400) for regulating an electrical machine (190), the method using a harmonic regulator (100), wherein the harmonic regulator comprises an input transformation (110), a regulator (120) and an output transformation (130), the method having the steps of: determining a feedback variable (Idq), wherein the feedback variable comprises an actual variable of a harmonic of a specified frequency in a field-oriented system; transforming the feedback variable (Idq) into a constant feedback variable (IHrmc) in a harmonic-oriented system by means of the input transformation (110); determining a regulation deviation as a difference between a specifiable constant control variable (IHrmc*) and the constant feedback variable (IHrmc) in the harmonic-oriented system; determining a constant steering variable (UHrmc*) from the regulation deviation by means of the regulator (120); inverse transforming the constant steering variable (UHrmc*) into a steering variable (UdqHrmc*) in the field-oriented system by means of the output transformation; energizing at least one winding of the electrical machine (190) in accordance with the steering variable (UdqHrmc*), wherein the feedback variable (Idq) in the field-oriented system comprises a first amplitude and a first phase of a harmonic having the electrical frequency of the electrical machine (190) of the k-th order with a positive frequency and / or a second amplitude and a second phase of a harmonic having the electrical frequency of the electrical machine (190) of the k-th order with a negative frequency.

2. The method according to claim 1, wherein the feedback variable (Idq) is transformed in accordance with a determined current rotor angle (w) of the electrical machine (190), and the transformation comprises a rotation by a rotation angle, which corresponds to k times the current rotor angle (w), and the rotation is effected in a positive direction and / or in a negative direction.

3. The method according to any one of the preceding claims, wherein the specifiable constant control variable (IHrmc*) of the harmonic-oriented system comprises a target variable in the harmonic-oriented system for generating a harmonic on a sinusoidal phase current to energize at least one winding of the electrical machine (190).

4. The method according to any one of the preceding claims, wherein the constant steering variable (UHrmc*) is determined by means of the regulator (120) by means of a regulation from the regulation deviation, the regulation using: a PI or I regulator; an inverse static or dynamic model and a PI or I regulator; or a regulator with an inverse static or dynamic model.

5. The method according to claim 1, wherein the constant steering variable (UHrmc*) is inverse transformed in accordance with a determined current rotor angle (w) of the electrical machine (190), and the inverse transformation comprises a rotation by a rotation angle, which corresponds to k times the current rotor angle (w), and the inverse transformation comprises a rotation in a positive and / or in an opposite negative direction, respectively, to the rotation of the feedback variable (Idq) by means of the input transformation (110).

6. The method according to claim 1, The method uses a fundamental regulator (200), wherein the fundamental regulator comprises a GW input transformation (210), a GW regulator (220) and a GW output transformation (230), The method has the following steps: determining a machine feedback variable (Iabc), wherein the machine feedback variable comprises actual variables of the electric machine; transforming the machine feedback variable (Iabc) into a feedback variable (Idq) in the field oriented system by means of the GW input transformation (210); determining a GW regulation deviation as a difference between a specifiable GW constant control variable (Idq*) and the feedback variable (Idq) in the field oriented system; determining a GW constant manipulated variable from the GW regulation deviation by means of the GW regulator (220); superimposing the GW constant manipulated variable with the manipulated variable (UdqHrmc*); inverse transforming the superimposed output variable into a machine manipulated variable (Uabc*) by means of the GW output transformation (230); and energizing at least one winding of the electric machine (190) in accordance with the machine manipulated variable (Uabc*).

7. The method according to claim 6, wherein the specifiable GW constant control variable (Idq*) of the field oriented system comprises target variables for generating a fundamental wave of sinusoidal phase currents to energize at least one winding of the electric machine (190).

8. A computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the processes / steps of the method (400) according to any one of claims 1 to 7.

9. A computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the processes / steps of the method (400) according to any one of claims 1 to 7.

10. An apparatus (300) for regulating an electric machine (190), The apparatus has a computing unit (310) and a harmonic regulator (100), wherein the harmonic regulator comprises an input transformation (110), a regulator (120) and an output transformation (130), wherein the apparatus is set up to carry out the steps of the method according to any one of claims 1 to 5.

11. The apparatus (300) according to claim 10, The apparatus has a fundamental regulator (200), wherein the fundamental regulator comprises a GW input transformation (210), a GW regulator (220) and a GW output transformation (230), wherein the apparatus is set up to carry out the steps of the method according to any one of claims 6 to 7.

12. An electric drive system (500) having an electric machine (190) and an apparatus (300) according to any one of claims 10 to 11.

13. A vehicle (600) having an electric drive system (500) according to claim 12.

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