DE102020129141B4 - Method for controlling a three-phase electric machine - Google Patents

Abstract

Method for controlling a three-phase electric machine (1), comprising at least the following steps:a. Providing a setpoint (45) for an operating variable of the electrical machine (1);b. Determining a reference data set (47) defining a fundamental oscillation based on the setpoint (45) and an estimated electrical angular velocity (46);c. Determining a harmonic data set (53) that defines a harmonic that is harmonic to the fundamental oscillation based on an input data set (51) that characterizes the fundamental oscillation and which includes input values (52), intermediate values being determined based on the input values (52) using look-up tables (27, 28, 29) for amplitudes, pilot control angles (66) and/or phases, are determined, with a harmonic frequency which corresponds to an integer multiple of the frequency of the fundamental oscillation; d. Determining a combination data set (54) by superimposing the harmonic harmonic and the fundamental oscillation to form an overall oscillation based on the harmonic data set (53) and the reference data set (47);e. Determining a control data record (44) of a converter (3) in a drive circuit (4) of the electrical machine (1) based on the combination data record (54);f. Acquiring current data (55) of a drive current, comprising at least measured current values from two phases of the drive circuit (4) of the electrical machine (1); and G. Determining the estimated electrical angular velocity (46) based on the current data (55) acquired in step f. and a harmonic angular velocity and a harmonic amplitude according to said harmonic.

Description

1. a. Bereitstellen eines Sollwerts für eine Betriebsgröße der elektrischen Maschine;
2. b. Ermitteln eines eine Grundschwingung definierenden Referenzdatensatzes anhand des Sollwerts und einer geschätzten Winkelgeschwindigkeit;
3. c. Ermitteln eines eine harmonische Oberschwingung definierenden Oberschwingungsdatensatzes anhand von einem die Grundschwingung kennzeichnenden Eingangsdatensatz;
4. d. Ermitteln eines Kombinationsdatensatzes mittels Überlagern der harmonischen Oberschwingung und der Grundschwingung zu einer Gesamtschwingung auf Grundlage des Oberschwingungsdatensatzes und des Referenzdatensatzes;
5. e. Ermitteln eines Steuerdatensatzes auf Grundlage des Kombinationsdatensatzes;
6. f. Erfassen von Stromdaten eines Antriebsstroms, umfassend zumindest gemessene Stromwerte des Antriebsstromkreises der elektrischen Maschine; und
7. g. Ermitteln der geschätzten Winkelgeschwindigkeit anhand der erfassten Stromdaten und einer Oberschwingungswinkelgeschwindigkeit und einer Oberschwingungsamplitude gemäß der harmonischen Oberschwingung. Die Erfindung betrifft weiterhin eine computergestützte Vorrichtung zum Ausführen eines solchen Verfahrens, sowie ein elektrifiziertes Kraftfahrzeug mit einem Bordcomputer zum Ausführen eines solchen Verfahrens.

The invention relates to a method for controlling a three-phase electric machine, with the following steps:

1. a. Providing a setpoint for an operating variable of the electrical machine;
2. b. Determining a reference data set defining a fundamental oscillation based on the setpoint and an estimated angular velocity;
3. c. Determining a harmonic data set defining a harmonic harmonic based on an input data set characterizing the fundamental frequency;
4. d. Determining a combination data set by superimposing the harmonic harmonic and the fundamental vibration to form a total oscillation based on the harmonic data set and the reference data set;
5. e. determining a control data set based on the combination data set;
6. f. Acquiring current data of a drive current, comprising at least measured current values of the drive circuit of the electric machine; and
7. G. Determining the estimated angular velocity based on the acquired current data and a harmonic angular velocity and a harmonic amplitude according to the harmonic. The invention further relates to a computer-aided device for carrying out such a method, as well as an electrified motor vehicle with an on-board computer for carrying out such a method.

The invention relates to a method for controlling an electrical machine and a device for carrying out the method. Three-phase-driven electrical machines are known from industrial practice. Such a three-phase electric machine is used, for example, as a drive machine in a motor vehicle. The coils of the electrical machines are subjected to a current or a voltage, with a phase angle shift occurring between the currents in the coils of a pole pair, so that the coils cause a rotation of the rotor in cooperation with a corresponding magnet (for example a permanent magnet).

Due to electromagnetic forces caused by the induction, mechanical oscillations (vibrations) can be generated in the rotor of the electrical machine. Because in synchronous machines the angular velocity of the electromagnetic forces causing the vibration is an integer multiple of the angular velocity of the phase current of the coils, a resonance oscillation can occur in the range of the resonance frequency of the structural environment. As a result, the resulting vibration of the rotor is amplified and may cause audible noises that are perceived as disturbing.

To reduce or avoid such noises, a so-called Active Noise Reduction [ANR] is often used. Harmonic harmonics are applied to the fundamental vibration, which dampen the noise caused by the electromagnetic forces, for example by describing the atomic number of the electromagnetic forces.

US 9,013,137 B2 discloses a device for calculating a rotational position of a three-phase rotating machine, wherein the device additionally reduces audible vibrations by means of a controllable inverter, which means a first diode and a first switch element connected in anti-parallel thereto and a second diode with a second switch element connected in anti-parallel thereto is controllable, can be represented. This means that the inverter is connected either to a positive connection or a negative connection of a DC voltage supply via one of the corresponding switching elements and thus a controlled variable of the rotating machine can be controlled. The rotation position is detected by detecting the high-frequency control signals of the rotating machine.

• 10.1109/IECON.2002.1187575 offenbart ferner eine Methode zur Verbesserung der sensorlosen Regelung für einen Permanentmagnet-Synchronmotor mit eingebetteten Magneten durch Unterdrückung der harmonischen Komponente des Stromregelkreises der Vektorregelung mittels Fouriertransformation und repetitiver Steuerung. Dabei werden zur Unterdrückung der Oberschwingungen Kompensationssignale mittels Fouriertransformation und repetitiver Kompensationssignale erfasst und eine Vorwärtsregelung mit den erfassten Kompensationssignalen implementiert. Hiervon ausgehend liegt der vorliegenden Erfindung die Aufgabe zugrunde, die aus dem Stand der Technik bekannten Nachteile zumindest teilweise zu überwinden. Die erfindungsgemäßen Merkmale ergeben sich aus den unabhängigen Ansprüchen, zu denen vorteilhafte Ausgestaltungen in den abhängigen Ansprüchen aufgezeigt werden. Die Merkmale der Ansprüche können in jeglicher technisch sinnvollen Art und Weise kombiniert werden, wobei hierzu auch die Erläuterungen aus der nachfolgenden Beschreibung sowie Merkmale aus den Figuren hinzugezogen werden können, welche ergänzende Ausgestaltungen der Erfindung umfassen.

KIM, Jeong-seong; DOKI, Shinji; ISHIDA, Muneaki: Improvement of IPMSM sensorless control performance by suppression of harmonics on the vector control using Fourier transform and repetitive control. In: IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02, November 5-8, 2002, Seville, Spain. 2002, pp. 597-602. ISBN 0-7803-7474-6. DOI:

• 10.1109/IECON.2002.1187575 further discloses a method for improving sensorless control for a permanent magnet synchronous motor with embedded magnets by suppressing the harmonic component of the vector control current control loop using Fourier transform and repetitive control. To suppress the harmonics, compensation signals are detected using Fourier transformation and repetitive compensation signals and a feedforward control is implemented with the detected compensation signals. Proceeding from this, the present invention is based on the object of at least partially overcoming the disadvantages known from the prior art. The features according to the invention result from the independent claims, to which advantageous embodiments are shown in the dependent claims. The features of the claims can be combined in any technically sensible manner, for which the explanations from the following description and features from the figures, which include additional embodiments of the invention, can also be consulted.

1. a. Bereitstellen eines Sollwerts für eine Betriebsgröße der elektrischen Maschine;
2. b. Ermitteln eines eine Grundschwingung definierenden Referenzdatensatzes anhand des Sollwerts und einer geschätzten elektrischen Winkelgeschwindigkeit;
3. c. Ermitteln eines eine zu der Grundschwingung harmonische Oberschwingung definierenden Oberschwingungsdatensatzes anhand von einem die Grundschwingung kennzeichnenden Eingangsdatensatz, welcher Eingangswerte umfasst, wobei Zwischenwerte anhand der Eingangswerte mittels Look-up-Tabellen für Amplituden, Vorsteuerwinkel (66) und/oder Phasen, ermittelt werden, mit einer Oberschwingungsfrequenz, welche einem ganzzahligen Vielfachen der Frequenz der Grundschwingung entspricht;
4. d. Ermitteln eines Kombinationsdatensatzes mittels Überlagern der harmonischen Oberschwingung und der Grundschwingung zu einer Gesamtschwingung auf Grundlage des Oberschwingungsdatensatzes und des Referenzdatensatzes;
5. e. Ermitteln eines Steuerdatensatzes eines Umrichters in einem Antriebsstromkreis der elektrischen Maschine auf Grundlage des Kombinationsdatensatzes;
6. f. Erfassen von Stromdaten eines Antriebsstroms, umfassend zumindest gemessene Stromwerte aus zwei Phasen des Antriebsstromkreises der elektrischen Maschine; und
7. g. Ermitteln der geschätzten elektrischen Winkelgeschwindigkeit anhand der in Schritt f. erfassten Stromdaten und einer Oberschwingungswinkelgeschwindigkeit und einer Oberschwingungsamplitude gemäß der genannten harmonischen Oberschwingung.

The invention relates to a method for controlling a three-phase electric machine, comprising at least the following steps:

1. a. Providing a setpoint for an operating variable of the electrical machine;
2. b. Determining a reference data set defining a fundamental oscillation based on the setpoint and an estimated electrical angular velocity;
3. c. Determining a harmonic data set defining a harmonic that is harmonic to the fundamental oscillation based on an input data set characterizing the fundamental oscillation, which includes input values, with intermediate values being determined based on the input values using look-up tables for amplitudes, pilot control angles (66) and/or phases, with a Harmonic frequency, which corresponds to an integer multiple of the frequency of the fundamental wave;
4. d. Determining a combination data set by superimposing the harmonic harmonic and the fundamental vibration to form a total oscillation based on the harmonic data set and the reference data set;
5. e. Determining a control data set of a converter in a drive circuit of the electrical machine based on the combination data set;
6. f. Acquiring current data of a drive current, comprising at least measured current values from two phases of the drive circuit of the electrical machine; and
7. G. Determining the estimated electrical angular velocity based on the current data acquired in step f. and a harmonic angular velocity and a harmonic amplitude according to said harmonic.

Ordinal numbers used in the preceding and following descriptions, unless explicitly stated to the contrary, only serve to clearly distinguish them and do not reflect the order or ranking of the designated components. An ordinal number greater than one does not mean that another such component must necessarily be present.

The steps of the method are preferably carried out in the order given.

In one embodiment, the three-phase electric machine is a so-called synchronous motor, which is installed in a motor vehicle and preferably serves as a drive for the motor vehicle. The method can be carried out by a processor, whereby the different method steps can be carried out by one or more processors.

The one in step a. In one embodiment, the setpoint provided will be determined by the or one of the processors that carry out the method. In an alternative embodiment, the setpoint is determined by another processor or another control unit. The setpoint preferably reflects a desired operating state value of the electrical machine. In one embodiment, the setpoint is dependent on the position of an acceleration value transmitter (for example the so-called accelerator pedal in a motor vehicle), which can be actuated by a user. Accordingly, a speed increase and/or load increase and/or load reduction can be adjusted using the setpoint. The setpoint preferably depends on an accelerator pedal position or another speed value, load value or speed value of a device which is used to control the speed of the motor vehicle and/or the operating range of the engine. Furthermore, the fundamental vibration calculation block receives an angle estimation data set which contains an estimated electrical angular velocity.

The one in step b. The reference data set determined includes reference current values. The reference data set preferably includes a current value for a d-axis, also called a longitudinal axis, and a current value for a q-axis, also called a transverse axis. The reference data set preferably indicates both the amplitude and the frequency or angular velocity of the fundamental oscillation.

The fundamental oscillation describes a (for example sinusoidal) wave function of a three-phase current, which is used to generate electromagnetic fields by means of the coils of the electrical machine, by means of which the rotor of the electrical machine rotates in cooperation with another magnet (preferably a permanent magnet). offset.

In step c. A harmonic that is harmonic to the fundamental is determined, which is applied to the fundamental. The harmonic is used to reduce noise. The harmonics have a harmonic frequency that corresponds to an integer multiple of the frequency of the fundamental. The harmonic serves to prevent noise caused by vibration of the rotor. The vibrations are caused by the fundamental vibration and its harmonic harmonics, which act on the rotor not only in the circumferential direction but also in the radial direction. The properties of the harmonics for reducing the noise of the electrical machine depend largely on the properties of the fundamental vibration and the electrical machine.

The sound waves often oscillate with an integer atomic number n. The atomic number indicates the multiple of the frequency of the sound wave to the frequency of the fundamental oscillation. The ordinal number of the noise is often 6 or 12. To dampen the noise, the ordinal number of the applied harmonic for noise reduction can preferably be n-1, n-2, n+1 or n+2.

In one embodiment, the data characterizing the fundamental oscillation (of the input data set) is motor data, which can be used, for example, to draw conclusions about the fundamental oscillation in a synchronous motor, for example the motor speed and/or the torque. In an alternative or additional embodiment, those data characterizing the fundamental oscillation can be current values that result from the measurements of the system response of the drive circuit and/or reference values that are output by the fundamental oscillation calculation block in the reference data set.

In a synchronous machine, the angular speed of the rotor and the electrical angular speed are almost the same. Therefore, in order to determine the harmonics in a particularly simple embodiment, it is sufficient if the data from the reference data set that describe the fundamental frequency are available to calculate the harmonic. In an alternative embodiment, additional motor data from the electric machine are available to calculate the harmonics. The engine data includes, for example, the engine torque, the engine speed and/or temperatures on the electric machine. Alternatively, the data from vibrations measured in the drive circuit are used. It is possible to draw conclusions from the engine data about the data describing the fundamental vibration and vice versa.

In one embodiment, the harmonic data set includes amplitude values and a value for an angular velocity, angle, or frequency of the harmonic. The amplitude value preferably indicates a voltage amplitude.

The one in step d. The combined data set determined represents a vibration in which the fundamental vibration and the harmonic vibration have been superimposed. If the harmonic and the fundamental oscillation are specified, for example, as vectors in a coordinate system, the individual vector rows of the harmonic data set and the reference data set can be added to one another depending on the coordinates.

In step e. In one embodiment, a signal is generated from the combined data set, which can be processed by the converter in order to enable the converter to generate the determined combined oscillation in a drive circuit. This is, for example, a voltage signal that a gate of the inverter is created. The voltage signal preferably contains the control data set.

The converter is preferably an indirect converter [VSI, English: Voltage Source Inverter] with one or more transistors. Each transistor has one or more gates which, by applying a voltage to the gate, increase or decrease the resistance in a conductor channel passing through the gate and thus reduce or prevent or increase or enable a current flow through the conductor channel. For example, the current flow in the three phases of the three-phase electric machine can be controlled.

The inverter is controlled via a control device. The control device is, for example, a central on-board computer of the motor vehicle or a computer integrated into the drive train. The control device supplies a control data set to the converter, for example comprising voltage signals for each of the three phases of the drive circuit of the electrical machine.

In step f., the system response in the drive circuit is sensed to determine the estimated electrical angle. The system response is recorded in the form of current values. In one embodiment, the amplitude values as well as an angle, an angular velocity and/or a frequency are recorded for each phase. Due to the uniform angular offset in a three-phase three-phase motor, in an alternative embodiment, the system response is determined in two phases and the current values of the third phase are determined based on the current values of the other two phases.

The data collected includes the fundamental vibration as well as the harmonic induced to reduce noise. In one embodiment, further oscillations, for example oscillations or deviations caused by the drive circuit itself, are also included in the recorded data. The collected data is summarized in the collection data set. The harmonic is preferably used to estimate the (estimated) electrical angle, which is why other oscillations, for example the fundamental oscillation, can be filtered out using high-pass filters and/or low-pass filters.

In one embodiment, the system response of the circuit is evaluated in the form of a current signal to a voltage signal applied to the circuit in order to draw conclusions about the position of the rotor. The estimated angular position of the rotor is then the estimated electrical angular position. The current signals and voltage signals used to estimate the estimated electrical angle preferably have the atomic number of the harmonic that is used to reduce noise.

In one embodiment, in step g. the previously determined estimated electrical angle from a calculation run, for example the first calculation run, for determining the estimated electrical angle is used to divide the current values in the subsequent calculation run, i.e. the second calculation run, for determining the estimated electrical angle the axes of the rotor-fixed coordinate system.

It is further proposed in an advantageous embodiment of the method that a step of controlling a coil current in the coils of the electrical machine by means of the converter based on the control data set is also included, wherein the converter runs along lines of the drive circuit of the electrical machine between a voltage source and the electrical machine is arranged.

It is further proposed in an advantageous embodiment of the method that step e. comprising transforming the data of the combination data set from a rotor-fixed coordinate system into phase-specific data and step f. comprising converting the current data from phase-specific data into the rotor-fixed coordinate system.

The rotor-fixed coordinate system can be designed to rotate with the rotor of the electrical machine. It preferably has a d-axis, also called a longitudinal axis, and a q-axis, also called a transverse axis. In order to be able to induce the data as oscillation in the drive circuit, the data of the combined data set must be converted so that it assigns at least one value to each phase of the drive circuit. On the other hand, the calculations are preferably carried out in the rotor-fixed coordinate system, so that the current data, which are determined in a phase-specific manner, are preferably first transferred back into the rotor-fixed coordinate system.

It is further proposed in an advantageous embodiment of the method that step c. continues to use the estimated electrical angular velocity and/or the current data to determine the harmonic data set.

It is further proposed in an advantageous embodiment of the method that step e. further comprises a pulse width modulation of the control data set for the converter carried out by means of a pulse width modulator.

It is further proposed in an advantageous embodiment of the method that step g. further includes determining an estimated angular difference between the estimated electrical angle and a measured electrical angle using an analytical equation, a phase look-up loop, an extended Kalman filter and/or a self-learning process.

It is further proposed in an advantageous embodiment of the method that the determination of the estimated electrical angular velocity in step g. is carried out based on the estimated angular difference and a time interval dependent on a sampling frequency.

It is further proposed in an advantageous embodiment of the method that the data characterizing the fundamental oscillation includes the torque of the electrical machine, the speed of the electrical machine and/or the angular velocity of the fundamental oscillation,
wherein those data characterizing the fundamental oscillation optionally further include the amplitude of the fundamental oscillation and/or temperature values of the electrical machine.

According to a further aspect, a computer-based device is proposed, comprising
at least one processor and a memory for carrying out a method according to one of the preceding methods.

Another aspect of the invention is a computer program comprising computer program code. The computer program code can be executed on at least one computer-based device, for example a so-called computer, so that the at least one computer-based device is caused to carry out the method according to an embodiment according to the above description.

In one embodiment, at least one computer-aided device, for example as an on-board computer, is integrated in a motor vehicle, for example with an electric motor drive train. Alternatively or additionally, the computer-aided device can be set up as a separate unit for communication with an on-board computer of a motor vehicle.

According to this embodiment, the method described can be computer-implemented. The computer-implemented method is stored as a computer program code, wherein the computer program code, when executed by a computer unit, preferably an on-board computer of a motor vehicle, causes the computer unit to carry out the method according to an embodiment according to the preceding description and thus to control the drive train of the motor vehicle .

The computer-implemented method is implemented, for example, by a computer program, the computer program comprising computer program code, the computer program code, when executed on a computer, causing the computer to carry out the method according to an embodiment as described above. Computer program code refers to one or more instructions or commands that cause a computer or processor to carry out a series of procedural steps, which represent, for example, an algorithm and/or other processing methods.

The computer program is preferably partially or completely executable on an on-board computer of a motor vehicle.

Furthermore, a computer program product is proposed on which the computer program code is stored as described above.

A computer program product is, for example, a medium such as RAM, ROM, an SO card, a memory card, a flash memory card or a disc. Furthermore, computer program products also include data sets stored on a server and downloadable.

• - zumindest ein Vortriebsrad;
• - eine drehstromgetriebene elektrische Maschine, welche zum Vortrieb des Kraftfahrzeugs mit dem zumindest einen Vortriebsrad drehmomentübertragend verbunden ist;
• - zumindest einen elektrischer Energiespeicher für die elektrische Maschine;
• - einen Umrichter, zum Phasen-gesteuerten Versorgen der elektrischen Maschine mit einer elektrischen Spannung aus der zumindest einen Spannungsquelle; und
• - zumindest einen Bordcomputer mit einem Prozessor und einem Speicher,

wobei der zumindest eine Bordcomputer dazu eingerichtet ist, ein Verfahren nach einer Ausführungsform gemäß der obigen Beschreibung zum Steuern der elektrischen Maschine auszuführen.According to a further aspect, an electrified motor vehicle is proposed, having at least the following components:

• - at least one driving wheel;
• - a three-phase-driven electric machine, which is connected to the at least one drive wheel in a torque-transmitting manner to propel the motor vehicle;
• - at least one electrical energy storage for the electrical machine;
• - a converter for supplying the electrical machine with an electrical voltage from the at least one voltage source in a phase-controlled manner; and
• - at least one on-board computer with a processor and memory,

wherein the at least one on-board computer is set up to carry out a method according to an embodiment according to the above description for controlling the electric machine.

The motor vehicle is, for example, an electrified passenger car, such as a Porsche Taycan. The propulsion wheels are set up to propel the motor vehicle and can be supplied with a corresponding torque by means of the at least one electric machine. For example, a speed sensor (traditionally referred to as an accelerator pedal) is provided in the driver's cab to regulate the propulsion. The speed sensor specifies the control value for the method for controlling the three-phase electric machine, by means of which the acceleration (and preferably also deceleration) of the motor vehicle can be set intuitively. In some embodiments, further input values are provided, in which, for example, vehicle values and/or traffic data are taken into account.

• 1: eine Regelkreisschema eines Verfahrens zum Steuern einer drehstromgetriebenen elektrischen Maschine;
• 2: eine schematische Darstellung der Berechnung der Oberschwingungen zur Geräuschreduzierung;
• 3: eine schematische Darstellung der Berechnung der Oberschwingungen zur Geräuschreduzierung in einer alternativen Ausführungsform;
• 4: eine schematische Darstellung einer Winkelschätzung eines geschätzten elektrischen Winkels;
• 5: eine schematische Darstellung einer Winkelschätzung eines geschätzten elektrischen Winkels in einer alternativen Ausführungsform; und
• 6: Kraftfahrzeug mit einer elektrischen Maschine.

The invention described above is explained in detail below against the relevant technical background with reference to the associated drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, although it should be noted that the drawings are not true to size and are not suitable for defining size relationships. It is presented in

• 1 : a control circuit diagram of a method for controlling a three-phase electric machine;
• 2 : a schematic representation of the calculation of harmonics for noise reduction;
• 3 : a schematic representation of the calculation of the harmonics for noise reduction in an alternative embodiment;
• 4 : a schematic representation of an angle estimate of an estimated electrical angle;
• 5 : a schematic representation of an angle estimate of an estimated electrical angle in an alternative embodiment; and
• 6 : Motor vehicle with an electric machine.

In 1 is until 5 schematic control circuits or sections thereof of a method for controlling a three-phase electric machine 1 are shown. The process steps are each represented as a block or using a mathematical symbol. The representation corresponds to a diagram common in control engineering, whereby the individual blocks do not have to be designed as separate hardware components, i.e. do not have to be elements of a hardware-implemented control loop. Rather, the control shown is preferably carried out on a computer-aided device, which is set up to carry out all method steps with one or more processors 89 and one or more memories 90. The computer-aided device has corresponding interfaces for indirect and/or direct communication with measuring sensors and control value transmitters.

The electrical machine 1 is preferably a synchronous machine. To power the electrical machine 1, a voltage source 2 is provided, which provides a voltage, preferably a direct voltage. The direct voltage is converted into a three-phase current by means of a converter 3, which is fed into the coils of the electrical machine 1 in order to cause a rotor of the electrical machine 1 to rotate. Each phase of the drive circuit 4 of the electrical machine 1 is connected to at least one coil. The current in the different phases is angularly offset. In a three-phase drive circuit 4, the angular offset between two coils is 120°.

The converter 3 is controlled via a control device 5. The control device 5 supplies a control data set 44 to the converter 3. The control data set 44 according to the illustrated exemplary embodiment contains voltage signals for each of the three phases of the drive circuit 4 of the electrical machine 1. The voltage signals are correspondingly applied to the gates of the converter 3 in order to control the current flow to influence in the respective phases.

The control device 5 carries out the calculation of a fundamental oscillation, a harmonic harmonic to the fundamental oscillation and an angle estimation.

The angle estimation makes it possible to determine the electrical angle in the phases of the drive circuit 4 without a sensor. In the case of a synchronous machine, the rotor angle of the electrical machine 1 is determined from this.

Determining the current specification in the d-axis and q-axis is in 1 shown schematically by the fundamental vibration calculation block 6. The fundamental vibration calculation block 6 receives a setpoint 45, usually the torque, as an input variable. Furthermore, the fundamental oscillation calculation block 6 uses the estimated angular velocity to determine the target current specification, which includes an estimated electrical angular velocity 46.

The fundamental oscillation calculation block 6 outputs reference current vectors 48 as output values, which contain data that describe the target fundamental oscillation in its amplitude.

The harmonic calculation block 7 schematically represents the calculation step for calculating the harmonic. For the sake of clarity, these input variables of the harmonic calculation block 7 are summarized under the input data set 51, without the corresponding arrow being connected to the possible sources of reference for the data.

It is also possible to use an estimated electrical angular velocity 46 or an estimated electrical angle 67 from the angle estimate as an input variable for determining the harmonic, as indicated by a separate arrow.

The harmonic determined by the harmonic calculation block 7 is described by the harmonic data set 53.

From the reference current vectors 48 and harmonic data set 53 determined by the fundamental oscillation calculation block 6 and the harmonic calculation block 7, a superposition oscillation is calculated according to an addition block 8, in which the harmonic oscillation is added to the fundamental oscillation. The superposition oscillation is described by the combination data record 54, which is an output variable of the addition block 8. In some embodiments, multiple harmonics of different atomic numbers are determined by one or more harmonic calculation blocks 7 and superimposed on the fundamental.

The combination data record 54 goes as input variables into a (first) control calculation block 9, which processes the data for use as control data in the converter 3 and sends it to the converter 3 as control data, for example as voltage values.

The estimation of the estimated electrical angle 67 and the estimated electrical angular velocity 46, which enters the fundamental oscillation calculation block 6 and the harmonic calculation block 7 as an estimation data set as input variables, takes place in an angle estimation block 12. The angle estimation block 12 estimates the estimated electrical angle 67 and the estimated electrical angular velocity 46 based on detection data of a detection data set provided by a (first) detection block 13 and further harmonic data of a white third harmonic data set, which is provided by the harmonic calculation block 7.

The further harmonic data or the harmonic comparison data set 60 preferably correspond to the harmonic data set 53 or its data correspond, include parts thereof or are designed differently. However, the harmonic comparison data set 60 preferably contains at least one angular velocity 46 and an amplitude of the harmonic.

To determine the detection data, the current is detected in at least two phases of the drive circuit 4 of the electric machine 1 and forwarded to the angle estimation block 12 as a detection data set. Based on the amplitudes and angle values of two phases of the three-phase drive circuit 4, the amplitudes and angle values in the third phase of the drive circuit 4 are determined, so that the data for all three phases are available. Alternatively, the current is recorded in all three phases.

In particular, the calculations of the fundamental oscillation and the harmonic oscillation can be carried out particularly easily if the oscillations are defined in a coordinate system that is fixed to the rotor (co-rotating) with the rotor of the electrical machine 1. For this purpose, the vibrations that were previously determined for each of the phases are transferred in the (first) detection block 13 into the rotor-fixed coordinate system, which has a longitudinal axis, also called the d-axis, and a transverse axis, also called the q-axis. Accordingly, the data of the combined oscillation must be divided again into the respective phases in order to be used by the converter 3 to control the drive circuit 4. This happens, for example, in the (first) control calculation block 9. This data conversion is off, for example 2 can be seen, which shows a method for controlling a three-phase electric machine 1.

In addition to the method steps already described, a pilot angle 66 is calculated in a pilot angle calculation block 16. The pilot control angle 66 flows as an input variable into a nonlinearity compensation block 17, by means of which system-related errors are compensated for or fluctuations are smoothed out. Correction voltages 64, which include the DC voltage provided by the voltage source 2 and possibly further voltage values (for example for calculating conductor losses), a time correction value 65 and an estimated future angle 70 flow as input variables into the non-linearity compensation block 17 a. The estimated future angle 70 can be determined, for example, as the sum of the estimated electrical angle 67 and the product of the estimated electrical angular velocity 46 and a time factor 68, where the time factor 68 is a multiple, for example 1.5 times [one and a half times] that Settlement time of the control loop is. In the present exemplary embodiment, the nonlinearity compensation block 17 outputs a compensation voltage value 61,62,63, per phase u,v,w of the drive circuit 4.

In the exemplary embodiment shown, the fundamental vibration calculation block 6 calculates a (first) reference current vector 48 with two reference current values according to the rotor-fixed coordinate system used. A measuring current vector is subtracted from the (first) reference current vector 48, which contains two current values according to the rotor-fixed coordinate system used, the current values being determined from the data measured in the drive circuit 4. In the exemplary embodiment shown, the measuring current vector corresponds to the acquisition data set of the current data 55. The data of the acquisition data set are output by a coordinate converter 22. The coordinate converter 22, which converts the phases u, v, w into the reference current values d, q of a reference current vector, is included in the (first) detection block 13 together with the subtraction block shown adjacent. In the coordinate converter 22, current signals which correspond to the system response 69 of the drive circuit 4 are converted from a phase-specific coordinate system into a rotor-fixed coordinate system.

The determined (second) current vector 49, which results from the difference between the reference current vector 48 and the measuring current vector 55, is converted into a reference voltage vector 50 with the voltage reference values using a proportional-integral controller. Furthermore, further control steps, for example a decoupling control, are carried out. This is represented here by the (first) decoupling control block 19 and the amplitude correction block 20.

The reference voltage vector 50, which includes those voltage reference values describing the fundamental oscillation, becomes a harmonic voltage vector of the harmonic data set 53 is added, which contains harmonic voltage values that describe the harmonic. In a division block 23, a phase-specific voltage value for each phase u,v,w is calculated from the combined voltage vector of the combination data set 54 determined in this way. A compensation voltage value 61, 62, 63 determined by the nonlinearity compensation calculation block is added to each of the phase-specific voltage values, which emerge as an output variable from the distribution block 23, and those values determined in this way are converted into pulse width modulation values of the control data by means of a pulse width modulator 18, so that they are of can be processed by the inverter 3.

The (first) reference current vector 48, the determined (second) reference current vector 49 and the reference voltage vector 50, with the respective reference values, correspond in one embodiment to the reference data set 47. The proportional-integral controller [PI controller], the (first) decoupling control block 19 , as well as the amplitude correction block 20, as well as the addition symbols, which are shown with plus signs and are arranged in the arrow sequence of the data sets of the harmonic data and the fundamental vibration data, are contained in the addition block 8 mentioned. The division block 23, the addition symbols which follow the division block 23 in phases, the non-linearity compensation block 17 and the PWM converter 18 are contained in the (first) control calculation block 9.

The angle estimation block 12 receives as input variables the angular velocity 46 and the amplitude of the harmonic from the harmonic calculation block 7 using the harmonic comparison data set 60 and the current values using the detection data set. From this, the estimated electrical angular velocity 46 and the estimated electrical angle 67 are calculated in the angle estimation block 12. Here, the estimated electrical angular velocity 46 is used to calculate the future angle 70, which serves as an input variable for the distribution block 23 and the nonlinearity compensation block 17, and is used as an input variable for the fundamental oscillation calculation block 6.

In 2 and 3 Possible embodiments for calculating the harmonic to reduce noise, also known as Active Noise Reduction [ANR], are shown. Accordingly, among other things, the harmonic calculation block 7 is shown there in greater detail. The calculations performed are divided into fast tasks and slow tasks. The slow tasks include calculation which is performed according to a slow frequency, preferably only every 0.1 ms [one tenth of a millisecond] to 500 ms [five hundred milliseconds], more preferably 0.5 ms to 1.5 ms, particularly preferably 0.75 to 1 .25 ms. The fast tasks include computation that is performed at a faster frequency than the computation of the slow tasks. The calculation of the fast tasks is preferably carried out at a frequency which corresponds to the frequency of the pulse width modulation (PWM frequency 75).

In the exemplary embodiment shown, the slow task area 32 of the harmonic calculation receives input values 52, which, for example, contain motor data, such as speed, temperatures or torque of the electric machine 1 and/or values that describe the harmonic oscillation, such as the current values of the detection data set, and/or an activation value 76 (for example a Boolean value), by means of which the noise reduction can be switched on or off. These input values 52 are, for example, the or part of the input data set(s) 51 (see 1 ).

Using analytical evaluations or look-up tables (LUT), shown here a first LUT block 27, second LUT block 28 and third LUT block 29 (for example for amplitudes, pilot control angle 66 and / or phases) are based on the input values 52 Intermediate values in a look-up data set 71 are transmitted to the fast task area 33. Furthermore, the values that were determined from the LUT are compared with limit values in a limitation block 31 and filtered accordingly and/or warning signals or switch-off signals are output for certain components if a limit value is exceeded.

In the area of fast tasks, the intermediate values of the look-up data set 71, as well as the additional intermediate values for an angle and angular velocity 46 calculated using the atomic number 72 of the harmonic, are provided in the frequency of the slow task area 32 and are used as input variables for the calculation of the voltage values of the Harmonic comparison data set 60 is used. For this purpose, the fast task area 33 in the difference calculator 91 continues to use the PWM frequency 75 and the motor speed 74 to determine a PWM angle difference 77. The pulse width modula tion angle difference serves as an input variable, which is introduced in the frequency of the fast task range (for example the PWM frequency 75). The PWM angle difference 77 (initial value of the difference calculator 91) indicates the angle by which the phase position of the harmonic moves during a cycle of the PWM frequency 75.

Alternatively to using the atomic number 72 in the harmonic calculation according to 3 It is also possible to use the harmonic frequency 73 to determine the intermediate values for an angle and an angular velocity 46 of the harmonic, as in 2 shown.

The voltage values of the harmonic comparison data set 60 determined by means of the harmonic calculation block 7 go as an input variable into the main control loop 24. There, the current vector of the detection data set is subtracted from the reference vector determined in the fundamental vibration calculation block 6. As already mentioned above 1 explained, the calculations or the processing steps are carried out according to the (second) decoupling control block 21 and the proportional-integral (PI) control element 26 before the harmonic vector of the harmonic data set 53 is added to the determined voltage vector after the PI control element 26 (at the addition symbol). becomes. The determined combination vector is then converted into control data for the converter 3 of the electrical machine 1 according to a (second) control calculation block 10, a (third) control calculation block 11 (inverse matrix multiplication) and with a pulse width modulator 18.

The control blocks 34, 35 in the harmonic calculation block 7 indicate the calculation of the sine value (two upper ones are each a sin control block 34) or the cosine value (the lower one is a cos control block 35) of the determined angle values. The blocks, each marked with an x symbol, multiply the determined cosine value and the sine values with an intermediate value of the voltage amplitude of the harmonic.

In the electrical machine 1, the current data 55 of those three phases processed by the pulse width modulator 18 and converter 3 are tapped. The current data 55 includes amplitudes and angles. In the present exemplary embodiment, a future angle 70 is determined by means of the settling time of the control loop and the estimated electrical angular velocity 46 by adding 1.5 times [one and a half times] the product of the estimated electrical angular velocity 46 and the settling time to a previously measured angle of the Current in the drive circuit 4 is estimated. This future angle 70 goes like in 3 shown as an input variable in the harmonic calculation block 7. The current data 55 are transmitted in a (second) acquisition block 14 into the Cartesian coordinate system and then in a (third) acquisition block 15 into the rotor-fixed coordinate system.

In the exemplary embodiment shown, the steps of the main control loop 24 run at a fast frequency in accordance with the fast task area 33.

Furthermore, a filter block 25 is provided, which performs a filter function 36 on the current vector. For this purpose, a filter value is determined in the filter block 25 based on the PWM frequency 75 and the engine speed using a (fourth) LUT block 30. The filter value is then sent to the filter function 36 for processing the current vector. The filter block 25 also has an activation value 76, which is a Boolean value and determines whether the filter function 36 is activated or not.

wobei V_ANR die Spannungsamplitude der Oberschwingung ist, ω_ANR die Winkelgeschwindigkeit 46 der Oberschwingung und φ_ANR eine Winkelverschiebung der Oberschwingung angibt. Dabei entspricht φ_ANR dem untersten Pfeil der Zwischenwerte des Oberschwingungskalkulationsblocks 7, ω_ANR dem zweituntersten und V_ANR dem obersten.That in the 2 and 3 The method presented involves setting up and solving equations. For example, at a pilot angle of -90°, the following harmonic voltage vector (of the harmonic data set 53 in 1 ) according to the in the 2 and 3 The method shown is introduced from the harmonic calculation block 7 into the main control loop 24: $$\left[\begin{array}{c}{v}_{d,ANR}\\ v_{q,ANR}\end{array}\right]=v_{ANR}\left[\begin{array}{c}\text{cos}\left({\omega }_{ANR}+{\phi }_{ANR}\right)\\ 0\end{array}\right]$$

where V _ANR is the voltage amplitude of the harmonic, ω _ANR is the angular velocity 46 of the harmonic and φ _ANR indicates an angular displacement of the harmonic. φ _ANR corresponds to the lowest arrow of the intermediate values of the harmonic calculation block 7, ω _ANR to the second lowest and V _ANR to the highest.

wobei die Matrix $$\left[\begin{array}{cc}{L}_{dd,ANR}& L_{qd,ANR}\\ L_{dq,ANR}& L_{qq,ANR}\end{array}\right]$$

die Induktionswerte der Spulen der elektrischen Maschine 1 für die Koordinatenachsen d und q beschreibt. Hierzu wurden einige Vereinfachungen getroffen, beispielsweise dass die Leitungswiderstände gegenüber den induktiven Widerständen vernachlässigbar sind und die geschätzte elektrische Winkelgeschwindigkeit 46 der Oberschwingung gegenüber der vorliegenden elektrischen Winkelgeschwindigkeit. Falls die differentiellen Induktivitäten L_dd,ANR und L_qq,ANR der Harmonischen nicht bekannt sind, sind auch die absoluten Induktivitäten L_d,ANR und L_q,ANR der Harmonischen verwendbar. Falls die die absoluten Induktivitäten L_d,ANR und L_q,ANR der Harmonischen nicht verwendet werden, sind auch die differentiellen Induktivitäten der Grundschwingung L_dd und L_qq verwendbar. Falls die differentiellen Induktivitäten der er Grundschwingung L_dd und L_qq nicht bekannt sind, sind auch die absoluten Induktivitäten L_d und L_q der Grundschwingung verwendbar.This results in a Δθ _el , which corresponds to the difference between the real or measured electrical angle θ _el and the estimated electrical angle θ̂ _el $$\begin{array}{l}\left[\begin{array}{c}{i}_{d,ANR}\\ i_{q,ANR}\end{array}\right]=\\ \frac{v_{ANR}}{{\omega }_{ANR}{L}_{dd,ANR}{L}_{qq,ANR}}\left[\begin{array}{c}\frac{L_{dd,ANR}+L_{qq,ANR}}{2}+\frac{L_{dd,ANR}-L_{qq,ANR}}{2}\text{cos}\left(2\Delta {\mathrm{\theta }}_{el}\right)\\ \frac{L_{dd,ANR}-L_{qq,ANR}}{2}\text{sin}\left(2\Delta {\mathrm{\theta }}_{el}\right)\end{array}\right]\text{sin}\left({\omega }_{ANR}t\right),\end{array}$$

where the matrix $$\left[\begin{array}{cc}{L}_{dd,ANR}& L_{qd,ANR}\\ L_{dq,ANR}& L_{qq,ANR}\end{array}\right]$$

describes the induction values of the coils of the electrical machine 1 for the coordinate axes d and q. For this purpose, some simplifications were made, for example that the line resistances are negligible compared to the inductive resistances and the estimated electrical angular velocity 46 of the harmonic compared to the existing electrical angular velocity. If the differential inductances L _dd,ANR and L _qq,ANR of the harmonics are not known, the absolute inductances L _d,ANR and L _q,ANR of the harmonics can also be used. If the absolute inductances L _d,ANR and L _q,ANR of the harmonics are not used, the differential inductances of the fundamental wave L _dd and L _qq can also be used. If the differential inductances of the fundamental wave L _dd and L _qq are not known, the absolute inductances L _d and L _q of the fundamental wave can also be used.

The 4 and 5 and represent the estimate of the electrical angle in an angle estimation block 12 in a switching-symbolic manner. The system response 69 (current signals) of the current vector, which are determined from each phase of the drive circuit 4, are converted into that with the rotor of the electrical in a difference calculator 91 Machine 1 is transformed into a rotor-fixed coordinate system with a d-axis and a q-axis. The current data 55 related to the rotor-fixed coordinate system (the reference number also applies to the lower signal processing path) passes through a high-pass filter 37, so that the signals of the fundamental oscillation are filtered out and the (first) processed measured values 56 remain from the measured current data 55 of the harmonic in a harmonic measurement current vector remain. An estimated electrical angle difference 79 is determined from the harmonic measurement current vector using the angle estimation block 12.

From the estimated angle difference 79, the estimated electrical angle 67 and the estimated electrical angular velocity 46 can be determined using a proportional-integral (PI) control element 26 and an integral control element 43.

The angle estimate shown determines the estimated electrical angle 67 based on the harmonic, which was determined in the harmonic calculation block 7 and was applied to the fundamental. Accordingly, the above-mentioned equation (2) for the current values i _d,ANR and i _q,ANR forms the basis for the calculation of the estimated electrical angle difference 79 Δθ̂̂ _el . This can be evaluated using phase lock loops, extended Kalman filters or analytical approaches to determine Δθ̂ _el .

An analytical possibility is given by the following equations, which are also in the 4 and 5 is shown graphically:

$$X_{d,ANR}=\frac{{\omega }_{ANR}{L}_{dd,ANR}{L}_{qq,ANR}}{V_{ANR}}LPF\left(i_{q,ANR}\text{sin}\left({\omega }_{ANR}t\right)\right)$$

wobei ein Anregungswinkelfaktor 39 sin(ω_ANRt), aus dem ersten prozessierten Messwert 56 die Stromwerte i_d,ANR und i_q,ANR multipliziert wird. Der dabei erzeugte zweite prozessierte Messwert 57 wird mittels eines Tiefpassfilters 38 gefiltert, sodass sich ein dritter prozessierter Messwert 58 ergibt, welcher mit einem induktiven Widerstandsterm $40\frac{{\omega }_{ANR}{L}_{dd,ANR}{L}_{qq,ANR}}{V_{ANR}}$

multipliziert wird und so den vierten prozessierten Messwert 59 ergibt. Dies führt unter Anwendung der Tiefpassfilter 38 zu den Gleichungen $$X_{d,ANR}=\frac{L_{dd,ANR}+L_{qq,ANR}}{2}+\frac{L_{qq,ANR}-L_{dd,ANR}}{2}\text{cos}2\Delta {\theta }_{el}$$

und $$X_{q,ANR}=\frac{L_{qq,ANR}-L_{dd,ANR}}{2}\text{sin }2\Delta {\theta }_{el}.$$

A harmonic inductance is calculated $$X_{d,ANR}=\frac{{\omega }_{ANR}{L}_{dd,ANR}{L}_{qq,ANR}}{v_{ANR}}LPF\left(i_{d,ANR}\text{sin}\left({\omega }_{ANR}t\right)\right)$$

$$X_{d,ANR}=\frac{{\omega }_{ANR}{L}_{dd,ANR}{L}_{qq,ANR}}{v_{ANR}}LPF\left(i_{q,ANR}\text{sin}\left({\omega }_{ANR}t\right)\right)$$

where an excitation angle factor 39 sin(ω _ANR t), the current values i _d,ANR and i _q,ANR are multiplied from the first processed measured value 56. The second processed measured value 57 generated in the process is filtered by means of a low-pass filter 38, so that a third processed measured value 58 results, which has an inductive resistance term $40\frac{{\omega }_{ANR}{L}_{dd,ANR}{L}_{qq,ANR}}{v_{ANR}}$

is multiplied and thus results in the fourth processed measured value 59. This leads to the equations using the low pass filters 38 $$X_{d,ANR}=\frac{L_{dd,ANR}+L_{qq,A\mathrm{<figure-callout\; id="2"\; label="N\; R"\; filenames="DE102020129141B4\_0012.png"\; state="\{\{state\}\}">N</figure-callout>}R}}{2}+\frac{L_{qq,ANR}-L_{dd,A\mathrm{<figure-callout\; id="2"\; label="N\; R"\; filenames="DE102020129141B4\_0012.png"\; state="\{\{state\}\}">N</figure-callout>}R}}{2}\text{<figure-callout id="2" label="cos" filenames="DE102020129141B4\_0012.png" state="{{state}}">cos</figure-callout>}2\Delta {\theta }_{el}$$

and $$X_{q,ANR}=\frac{L_{qq,ANR}-L_{dd,A\mathrm{<figure-callout\; id="2"\; label="N\; R"\; filenames="DE102020129141B4\_0012.png"\; state="\{\{state\}\}">N</figure-callout>}R}}{2}\text{<figure-callout id="2" label="sin" filenames="DE102020129141B4\_0012.png" state="{{state}}">sin</figure-callout>}2\Delta {\theta }_{el}.$$

From equations (6) and (7), in an arc-tan controller 41, using an arc-tan function and subtracting an average inductance value 42 from the value of the d-axis Δθ̂ _el (also called the longitudinal axis) results in $$\Delta {\widehat{\theta }}_{\text{el}}=\frac{1}{2}{\text{tan}}^{-1}\left(\frac{X_{q,ANR}}{X_{d,ANR}-\frac{L_{dd,ANR}+L_{qq,ANR}}{2}}\right).$$

ist, wie in 4 dargestellt. Dabei stellt der Induktivitätsfaktor 78 den Faktor $\frac{L_{qq,ANR}-L_{dd,ANR}}{2}$

dar.By assuming that the estimation errors of the angle estimation are small, the simplification can be made that $$X_{q,ANR}\approx 2\frac{L_{qq,ANR}-L_{dd,A\mathrm{<figure-callout\; id="2"\; label="N\; R"\; filenames="DE102020129141B4\_0012.png"\; state="\{\{state\}\}">N</figure-callout>}R}}{2}\Delta {\theta }_{el}$$

is, as in 4 shown. The inductance factor 78 represents the factor $\frac{L_{qq,ANR}-L_{dd,A\mathrm{<figure-callout\; id="2"\; label="N\; R"\; filenames="DE102020129141B4\_0012.png"\; state="\{\{state\}\}">N</figure-callout>}R}}{2}$

represents.

In 6 a motor vehicle 80 is shown in a schematic top view. (Optionally) an (optionally electric) machine 1 is arranged in the rear area, which is connected to a left rear propulsion wheel 81 and a right rear propulsion wheel 82 via a gearbox 85 and a differential 86 to propel the motor vehicle 80. In the area of the front of the motor vehicle 80, a left front propulsion wheel 83 and a right front propulsion wheel 84 are arranged, preferably steerable, which (optionally additionally or alternatively) are also connected to a second (optionally electric) machine 1 in a torque-transmitting manner for propulsion. Here (optionally between the rear propulsion wheels 81, 82 and the front propulsion wheels 83, 84) an electrical energy storage device 88 is included, preferably designed as a traction battery, as a voltage source 2 for at least one of the electric machines 1. Furthermore, an on-board computer 87 comprising a ( Data) memory 90 and a (data) processor 89 are shown, which controls the supply of the (here two) electrical machines 1, preferably according to a method according to a previously described embodiment.

With the method proposed here, an electrical machine can be controlled without sensors, while at the same time a resonance oscillation can be prevented.

Reference symbol list

1

electric machine

2

voltage source

3

Inverter

4

Drive circuit

5

Control device

6

Fundamental vibration calculation block

7

Harmonic calculation block

8th

Addition block

9

first control calculation block

10

second control calculation block

11

third control calculation block

12

Angle estimation block

13

first capture block

14

second capture block

15

third capture block

16

Pilot angle calculation block

17

Nonlinearity compensation block

18

Pulse width modulator (PWM converter)

19

first decoupling control block

20

Amplitude correction block

21

second decoupling control block

22

Coordinate converter

23

Splitting block

24

Main control loop

25

Filter block

26

Proportional-integral (PL) control element

27

Look-up tables (LUT) block

28

second LUT block

29

third LUT block

30

fourth LUT block

31

Boundary block

32

slow task area

33

quick task scope

34

sin control block

35

cos control block

36

Filter function

37

High pass filter

38

Low pass filter

39

Excitation angle factor

40

inductive resistance term

41

Arc Tan control

42

Average inductance value

43

Integral control element

44

Tax record

45

Setpoint

46

estimated electrical angular velocity

47

Reference dataset

48

Reference current vector

49

determined reference current vector

50

Reference voltage vector

51

Input data set

52

Input value

53

Harmonic data set

54

Combination data set

55

Electricity data

56

first processed measured value

57

second processed measured value

58

third processed measured value

59

fourth processed measured value

60

Harmonic comparison data set

61u

Compensation voltage value

62v

Compensation voltage value

63f

Compensation voltage value

64

Correction voltage

65

Time correction value

66

Pilot angle

67

estimated electrical angle

68

Time factor (settling time)

69

System response (current signals)

70

estimated future angle

71

Look-up table record

72

atomic number

73

Harmonic frequency

74

Engine speed

75

PWM frequency

76

Activation value

77

PWM angle difference

78

inductance factor

79

electrical angle difference

80

motor vehicle

81

left rear driving wheel

82

right rear drive wheel

83

left front drive wheel

84

right front drive wheel

85

transmission

86

differential

87

On-board computer

88

electrical energy storage

89

processor

90

Storage

91

Difference Calculator

Claims (8)

Method for controlling a three-phase electric machine (1), comprising at least the following steps: a. Providing a setpoint (45) for an operating variable of the electrical machine (1); b. Determining a reference data set (47) defining a fundamental oscillation based on the setpoint (45) and an estimated electrical angular velocity (46); c. Determining a harmonic data set (53) defining a harmonic that is harmonic to the fundamental oscillation based on an input data set (51) characterizing the fundamental oscillation, which includes input values (52), intermediate values being determined based on the input values (52) using look-up tables (27, 28, 29) for amplitudes, pilot control angles (66) and/or phases, are determined, with a harmonic frequency which corresponds to an integer multiple of the frequency of the fundamental vibration; d. Determining a combination data set (54) by superimposing the harmonic harmonic and the fundamental oscillation to form an overall oscillation based on the harmonic data set (53) and the reference data set (47); e. Determining a control data record (44) of a converter (3) in a drive circuit (4) of the electrical machine (1) based on the combination data record (54); f. Acquiring current data (55) of a drive current, comprising at least measured current values from two phases of the drive circuit (4) of the electrical machine (1); and G. Determining the estimated electrical angular velocity (46) based on the current data (55) acquired in step f. and a harmonic angular velocity and a harmonic amplitude according to said harmonic. Procedure according to Claim 1 , where step c. continues to use the estimated electrical angular velocity (46) and/or the current data (55) to determine the harmonic data set. Procedure according to Claim 1 or 2 , where step e. further comprises a pulse width modulation of the control data set (44) for the converter (3) carried out by means of a pulse width modulator (18). Method according to one of the preceding claims, wherein step g. further comprises determining an estimated angular difference (79) between the estimated electrical angle and a measured electrical angle using an analytical equation, a phase look-up loop, an extended Kalman filter and/or a self-learning process. Procedure according to Claim 4 , wherein determining the estimated electrical angular velocity (46) in step g. is carried out based on the estimated angle difference (79) and a time interval dependent on a sampling frequency. Method according to one of the preceding claims, wherein those data characterizing the fundamental oscillation include the torque of the electrical machine (1), the speed of the electrical machine (1) and / or the angular velocity (46) of the fundamental oscillation, wherein those data characterizing the fundamental oscillation optionally further the amplitude of the fundamental oscillation and/or temperature values of the electrical machine (1). Computer-based computer-based device (87), comprising at least one processor (89) and a memory (90) for carrying out a method according to one of the preceding methods. Electrified motor vehicle (80), having at least the following components: - at least one propulsion wheel (81,82,83,84); - a three-phase electric machine (1), which is connected to the at least one drive wheel (81,82,83,84) in a torque-transmitting manner to propel the motor vehicle (80); - at least one electrical energy storage (88) for the electrical machine (1); - a converter (3) for supplying the electrical machine (1) with an electrical voltage from the at least one voltage source (2) in a phase-controlled manner; and - at least one on-board computer (87) with a processor (89) and a memory (90), the at least one on-board computer (87) being set up to implement a method according to one of Claims 1 until 6 to control the electrical machine (1).

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