Method for modulating torque ripple and / or radial forces of a three-phase current operated type

Abstract

A method for modulating torque pulsations and / or radial forces of a three-phase current-operated electric machine (10), in particular of an electric drive machine of a motor vehicle which can be driven by an electric motor, the method comprising the following method steps: - selecting at least one harmonic in the torque of the electric machine (10) and / or at least one harmonic of a load (20) coupled to the electric machine (10), wherein the selected at least one harmonic is modulated by applying the selected at least one harmonic to a d current and / or a q current or to a variable related to the d current and / or the q current in order to generate a setpoint variable (w) for driving the electric machine (10), wherein the phase angle of the harmonic in the d current (Id) and / or the phase angle of the harmonic in the q current (Iq) is at least temporarily set to be different with respect to the rotor angle.

Description

Technical Field

[0001] The present invention relates to a method for modulating torque pulsations and / or radial forces of a three-phase current-operated motor, particularly torque pulsations and / or radial forces of an electric drive machine of a motor vehicle capable of being driven by an electric motor, the method comprising the steps of: selecting at least one harmonic in the torque of the motor and / or selecting at least one harmonic of a component connected to the motor. Background Technology

[0002] DE 10 2014 208 384 A1 discloses a method for reducing gear meshing noise in an electrically driven transmission system having a toothed gear transmission and an electric motor. The method includes the steps of: determining the operating state of the transmission system (10); reading a dataset associated with the determined operating state from a data memory; and adjusting the torque of the electric motor based on the dataset. It is proposed to apply a torque signal to the transmission, which counteracts vibration or noise from the transmission. The signal used to compensate for the torque is added to other desired torques, such as static drive torque.

[0003] DE 10 2014 007 502 A1 discloses a method for noise modulation of an electric motor, wherein the electric motor is a three-phase synchronous motor driven by a motor control unit using vector control, wherein actual values ​​for the rotational current components id and iq are obtained in the controlled system, wherein id corresponds to the magnetizing current of the synchronous motor and iq corresponds to the torque-forming current of the synchronous motor, and wherein the actual values ​​are compared with specified reference variables (iq_set, id_set). The difference between the actual values ​​and the reference variables is converted into manipulated variables via a first controller and a first transition phase in the duty cycle of a PWM generator, so as to adjust the actual values ​​(iq, id) to the reference variables (iq_set, id_set). Additionally, the current component (id) forming the magnetizing current is adjusted to the desired acoustic state by means of an acoustic controller based on the acoustic state that has been measured by a measuring device and forwarded to the motor control unit by means of a signal output.

[0004] Furthermore, DE 10 2009 000 928 A1 describes a method for reducing torque ripple in an electric motor. The method includes receiving a torque command and determining a cancellation current command based on the torque command. The method also includes generating a harmonic cancellation command based on the cancellation current command, wherein the harmonic cancellation command compensates for phase shift and damping caused by a current-regulated control module, and wherein the current-regulated control module is coupled to an inverter coupled to the electric motor. The method further includes providing the harmonic cancellation command to the current-regulated control module, wherein the current-regulated control module is configured to control the inverter in response to the harmonic cancellation command and the torque command. Summary of the Invention

[0005] The object of the present invention is to provide a method for modulating torque ripple and / or radial force in a three-phase current-operated motor, which improves upon the type of modulation. Advantageously, a method is provided that reduces torque ripple or radial force of the electrically driven machine occurring in the drivetrain of an electrically operable motor vehicle compared to methods known in the prior art, and thus further reduces noise emissions in the vehicle.

[0006] Therefore, the method according to the present invention includes the following method steps:

[0007] At least one harmonic in the torque of the selected motor and / or at least one harmonic in a component of the selected motor's transmission system connected to the motor. According to the invention, the selected at least one harmonic is modulated by applying it to the d current and / or q current, or to a variable related to the d current and / or q current, such as the stator voltage of the motor or the magnetic flux within the motor, to generate a setpoint variable for driving the motor, wherein...

[0008] The phase angles of the harmonics of the d-current and / or the harmonics of the q-current are set at least temporarily to be different relative to the rotor angle, such that the phase angle of the d-component is at least temporarily not equal to the phase angle of the q-component. Therefore, the bandwidth for modulation types affecting vibrations and / or noise generated by components in the motor or the drivetrain of a motor vehicle is significantly increased, and thus the possibility of responding to these effects is improved.

[0009] Therefore, the method according to the invention reduces the harmonics of the motor torque or the torque in the transmission system by applying harmonics to the d current or q current, particularly in a targeted manner, and thus reduces vibration and noise. However, in addition to reducing harmonics, these harmonics can also be easily adjusted to the desired specifications. This current can be represented by amplitude and phase:

[0010]

[0011]

[0012] Other advantageous embodiments of the invention are described in detail in the dependent claims. Features listed separately in the dependent claims may be combined with each other in a technically meaningful manner and may define other embodiments of the invention. Furthermore, the features indicated in the claims are described and explained in more detail in the specification, wherein other preferred embodiments of the invention are shown.

[0013] According to an advantageous embodiment of the invention, at least one harmonic in the torque of the motor and / or at least one harmonic of a component connected to the motor can be selected, and the selected at least one harmonic can be modulated by applying the selected at least one harmonic to the d current and / or q current or to a related variable, so as to drive the motor under conditions where the torque of the motor and / or the torque of the transmission system tends to be smooth, thereby reducing vibration and noise. From all possible combinations of d current and q current that reduce harmonics in the torque in a targeted manner, there are combinations that result in the lowest current amplitude, voltage amplitude, loss amplitude, etc. This achieves the advantage that the torque of the motor or the torque of the transmission system connected to the motor can tend to be smooth, so that unwanted vibration and noise can be damped in a significantly improved manner.

[0014] According to other preferred improvements of the invention, the d current and / or q current can also be selected such that the magnitude of the resulting stator voltage is...

[0015] Or the magnitude of the generated stator current

[0016]

[0017] The result is minimized, where the d-component of the stator voltage is as follows:

[0018]

[0019] Furthermore, the q-component of the stator voltage is as follows:

[0020]

[0021] In this respect, the magnitude of the induced voltage is independent of the speed of the motor and the change in the magnetic flux in the motor.

[0022] motor torque

[0023]

[0024] This is independent of the magnetic flux and the current in the D direction and the current in the q direction. This results in a significantly higher number of combinations, which, in addition to applying the motor through i d1and i q1 In addition to the torque, an additional force was applied via i dk and i qk Additional torque (M) k ). Used for torque M k The current can be selected using the previously described degrees of freedom to satisfy additional conditions, such as a minimum amplitude for the stator voltage amplitude or a minimum amplitude for the stator current amplitude. This provides the advantage that a smaller voltage space vector (by minimizing the stator voltage amplitude) also allows the motor to operate near voltage limits—for example, in the lower voltage limit region when the battery is relatively empty—or in the higher voltage limit region when the motor is operating at full load for acceleration.

[0025] Furthermore, according to equally advantageous embodiments of the present invention, it is possible that:

[0026] - Harmonics are calculated to generate setpoint variables using the following method steps that will be performed.

[0027] - Modeling the motor's torque or radial force, or the resulting oscillations, with the aim of minimizing torque ripple by considering induced voltage and / or radial force, or minimizing radial force by considering induced voltage, and

[0028] - By taking into account the induced voltage, torque pulsations and / or radial forces are generated, and

[0029] - The induced voltage is modeled by taking into account torque ripple and / or radial force.

[0030] According to another particularly preferred embodiment of the invention, in order to generate the setpoint variables for driving the motor, the d current, q current, and d phase angle and q phase angle can be read from a table.

[0031] Advantageously, variables can be read from four different tables to generate setpoint variables for driving the motor, wherein two of these tables each contain the amplitude of the d variable and the amplitude of the q variable, and wherein the other two tables each contain the relevant phase of the d variable and the relevant phase of the q variable. Alternatively, to generate setpoint variables for driving the motor, variables can be read from four different tables, wherein two of these tables each contain the true amplitude values ​​of the d variable and the true amplitude values ​​of the q variable, and the other two tables each contain the virtual amplitude values ​​of the d variable and the virtual amplitude values ​​of the q variable. Another possibility for generating setpoint variables to drive the motor is that variables can be read from a table that specifically contains only amplitude variables, wherein other required variables are determined according to predetermined rules. Attached Figure Description

[0032] The invention and the technical field are described in more detail below with reference to the accompanying drawings. It should be noted that the invention is not intended to be limited to the exemplary embodiments shown. In particular, unless explicitly stated otherwise, certain aspects of the essential content outlined in the drawings may be extracted and combined with other components and knowledge from this specification and / or the drawings. In particular, it should be noted that the drawings, and especially the scale shown, are merely schematic in nature. The same reference numerals indicate the same objects, allowing for the use of descriptions based on other drawings.

[0033] In the attached diagram:

[0034] Figure 1 A block diagram illustrates the transmission system of an electrically driven motor vehicle.

[0035] Figure 2 The top graph shows the torque curves of the motor under three different drive conditions, and the bottom graph shows the torque curves on the stator of the corresponding driven motor. Figure 2 The voltage curve associated with the torque curve shown above,

[0036] Figure 3 A more detailed diagram is shown from Figure 1 A block diagram of the control and adjustment unit.

[0037] Figure 4 A more detailed diagram is shown from Figure 1 Block diagram of the setpoint generator.

[0038] Figure 5 The comparison shows the source Figure 4 Block diagrams of harmonics according to the prior art and block diagrams of harmonics according to the present invention, and

[0039] Figure 6 An extended diagram is shown from Figure 4 A block diagram of the setpoint generator. Detailed Implementation

[0040] Figure 1A block diagram illustrates a schematic of the drivetrain 100 of an electrically driven motor vehicle. A motor 10 is mechanically coupled to a load 20, such as the drive shaft of the motor vehicle, on its output side. On the input side, the motor 10 is driven by a power electronics unit 30, which, for example, supplies three-phase current to the stator windings of the motor 10. For this purpose, the power electronics unit is connected to an energy source 40, such as the vehicle's onboard battery, where the DC voltage or current supplied by the battery is converted into three-phase current via a corresponding inverter in the power electronics unit 30. The power electronics unit 30 is connected via another interface on its input side to a control / regulation unit 50, which drives the power electronics unit according to the setpoint specifications of a setpoint generator 60 connected to the input side. In this regard, the control / regulation unit 50 optionally sets, via corresponding sensors, operating variables of the motor 10, operating variables of the load 20 driven by the motor 10, and operating variables of the energy source 40 supplying the power electronics unit 30 or the motor 10; these operating variables are important for driving the motor 10.

[0041] Figure 2 The figure above shows the torque curves of motor 10 under three different drive conditions. The first torque curve M1 (solid line) shows the torque occurring when motor 10 is driven according to the prior art with sinusoidal excitation without harmonic components. The second torque curve M2 (dashed line) shows the torque occurring according to the prior art with sinusoidal excitation having standard harmonic components. Finally, in contrast, the remaining third torque curve M3 (dashed line) shows the torque occurring according to the invention with sinusoidal excitation having harmonic components, wherein the d variable and / or q variable have phase angles that are at least temporarily different from the rotor angle.

[0042] Figure 2 The diagram below shows the stator of the corresponding driven motor 10 and... Figure 2 The voltage curves are associated with the torque curves shown above. The first voltage curve U1 (solid line) shows the voltage that occurs when the motor 10 is driven according to the prior art with sinusoidal excitation without harmonic components. The second voltage curve U2 (dotted line) shows the voltage curve that occurs according to the prior art with sinusoidal excitation having standard harmonic components. Finally, in contrast, the remaining third voltage curve U3 (dashed line) shows the voltage curve that occurs according to the invention with sinusoidal excitation having harmonic components, wherein the d variable and / or q variable have phase angles that are at least temporarily different from the rotor angle. The examples shown clearly demonstrate that the same torque can be provided using the method according to the invention as with conventional methods, wherein a significantly lower voltage amplitude is required.

[0043] Figure 3 A more detailed diagram is shown from Figure 1 A block diagram of the control / regulation unit 50 is shown. The control / regulation unit 50 is shown with static input variables I having its d current and q current. d0 and I q0 It also has a dynamic d-input variable I that changes according to the rotor angle. dk and dynamic q input variable I dq On the output side, the setpoint variable U used to drive the power electronics unit 30 is shown. a, b, c The setpoint / actual value comparison and corresponding adjustment can be performed using additional components or by filtering the dynamic portion of the setpoint / actual value comparison and then adding that dynamic portion again during the subsequent adjustment process (the so-called dynamic portion being a blind voltage application).

[0044] Figure 4 A more detailed diagram is shown from Figure 1 The block diagram shows a setpoint generator 60, which is used to assign setpoint values ​​to the control / regulation unit 50. The setpoint generator 60 shown provides input variables to the control / regulation unit 50 on the output side, as already referenced above. Figure 3 This has been explained. These input variables are generated by modeling the torque request using the torque section 61, where the harmonics H in the torque of the motor 10 are... M1_EM and / or the harmonics H of the load 20 connected to the motor 10 in the transmission system. M_X Selected. Then, by selecting at least one harmonic H M1_EM H M_X Applying current d and / or current q to modulate at least one selected harmonic H M1_EM H M_X This is to generate the setpoint variable w for driving motor 10. The harmonics H in the current Id. Id Harmonics H in the current Iq and / or q Iq phase angle , Relative to rotor angle At least temporarily set them to be different, so that they are applicable ≠ The phase angles of the currents (Id, Iq) (relative to the rotor angle) can therefore be set independently of Id and Iq, so that if this is advantageous, the phase angles can be set differently.

[0045] The computational strategy upon which the harmonic component 62 is based includes at least the following:

[0046] - Modulation of torque and / or radial force,

[0047] - Minimize torque ripple by taking into account induced voltage and / or radial force.

[0048] - Minimize radial force by taking into account torque ripple and / or induced voltage.

[0049] - Generating torque pulsations and / or radial forces by taking induced voltage into account.

[0050] - Modulate the induced voltage by taking into account torque pulsation and / or radial force.

[0051] Optionally, the harmonic section 62 receives input variables externally in the form of pulsation requests and internally receives input variables from the torque section 61. On the output side, both the static variable as an input variable for the control / regulation unit 50 and the dynamic variable as an input variable for the control / regulation unit 50 are then provided by the torque section 61 through the setpoint generator 60.

[0052] Figure 5 The comparison shows the source Figure 4 The diagram above shows a block diagram of the harmonic section 62 according to the prior art, and the diagram below shows a block diagram of the harmonic section according to the present invention. It is easy to see that, according to the present invention, the phase angles of the d current and the q current are completely different.

[0053] Figure 6 An extended diagram is shown from Figure 4 A block diagram of the setpoint generator 60. (Already...) Figure 4 The diagram of the setpoint generator 60 shown and described in this embodiment is extended by the corresponding table section 63, which is used to generate the setpoint variable w for driving the motor 10. For example, the d current Id, q current Iq, and d phase angle can be read from the table. and q phase angle .

[0054] To generate the setpoint variable w for driving the motor 10, variables can be read from four different tables, where two of these tables each contain the amplitude of the d variable and the amplitude of the q variable, and the other two tables each contain the relevant phase of the d variable and the relevant phase of the q variable. Alternatively, to generate the setpoint variable for driving the motor, variables can be read from four different tables, where two of these tables each contain the actual amplitude values ​​of the d variable and the actual amplitude values ​​of the q variable, and the other two tables each contain the virtual amplitude values ​​of the d variable and the virtual amplitude values ​​of the q variable. Finally, to generate the setpoint variable for driving the motor, variables can be read from a table that specifically contains only amplitude variables, where other required variables are determined according to predetermined rules.

[0055] This invention is not limited to the embodiments shown in the accompanying drawings. Therefore, the above description is not to be considered limiting, but rather illustrative. The appended claims should be understood to mean that the specified features are present in at least one embodiment of the invention. This does not exclude the presence of other features. If the patent claims and the foregoing description define "first" and "second" features, such designation is used to distinguish two features of the same type without specifying a priority order.

[0056] List of reference numerals

[0057] 10 motors

[0058] 20 Load (Transmission System)

[0059] 30 Power Electronics Unit

[0060] 40 Battery / Energy Components

[0061] 50 Control / Regulation Units

[0062] 60 Setpoint Generator

[0063] 61 Torque Section

[0064] 62 Harmonic Section

[0065] Table 63

[0066] 100 Transmission System

Claims

1. A method for modulating torque ripple and / or radial force of a three-phase current-operated motor (10), the method comprising the following steps: - At least one harmonic of the torque of the selected motor (10) and / or at least one harmonic of the load (20) of the selected transmission system (100) connected to the motor (10), characterized in that - The selected at least one harmonic is modulated by applying the selected at least one harmonic to the d current and / or the q current or to a variable associated with the d current and / or the q current, so as to generate a setpoint variable (w) for driving the motor (10), wherein the phase angle of the harmonic in the d current (Id) and / or the harmonic in the q current (Iq) is ( , ) relative to the rotor angle ( (At least temporarily) are set to be different, making ≠ Applicable; In order to generate the setpoint variable (w) - Calculate harmonics by performing the following steps: - The torque of the motor (10) is modeled with the aim of minimizing torque ripple by taking into account the induced voltage and / or the radial force, or with the aim of minimizing the radial force by taking into account the induced voltage, and - By taking into account the induced voltage, torque pulsations and / or radial forces are generated, and - The induced voltage is modeled by taking into account the torque pulsation and / or the radial force.

2. The method according to claim 1, characterized in that, - Select at least one harmonic of the torque of the selected motor (10) and / or select at least one harmonic of the load (20) of the transmission system (100) connected to the motor (10), and The selected at least one harmonic is modulated by applying the selected at least one harmonic to the d current (Id) and / or the q current (Iq) or to a variable related to the d current (Id) and / or the q current (Iq) to drive the motor (10) with the torque of the motor (10) and / or the torque of the transmission system (100) tending to be smooth, thereby reducing vibration and noise.

3. The method according to claim 1, characterized in that, The d current (Id) and / or the q current (Iq) are selected such that the magnitude of the resulting stator voltage is... Or the magnitude of the generated stator current Minimized in, and 。 4. The method according to any one of the preceding claims, characterized in that, To generate the setpoint variable (w) for driving the motor (10), the d current (Id), the q current (Iq), and the d phase angle ( ) and q phase angle ( It can be read from the table.

5. The method according to claim 4, characterized in that, To generate the setpoint variable (w) for driving the motor, the variable can be read from four different tables, wherein two of the tables each contain the amplitude of the d variable and the amplitude of the q variable, and wherein, The other two tables each contain the relevant phase of the aforementioned d variable ( ) and the correlation phase of the q variable ( ).

6. The method according to claim 4, characterized in that, To generate the setpoint variable (w) for driving the motor, variables are read from four different tables, wherein two of the tables each contain the actual amplitude values ​​of the d variable and the q variable, and wherein the other two tables each contain the virtual amplitude values ​​of the d variable and the q variable.

7. The method according to claim 4, characterized in that, In order to generate the setpoint variable (w) for driving the motor, the variable can be read from a table containing only the amplitude variable, wherein other required variables are determined according to predetermined rules.

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