METHOD AND DEVICE FOR CALIBRATING THE CONTROL OF AN ELECTRICAL MACHINE

Abstract

The invention relates to a method (400) for calibrating the control of an electrical machine (120) for a specifiable torque value (T_Des), the electrical machine (120) being operated by means of field-oriented control. The method comprises the steps of: a.) specifying a current vector (Ix_V) (410) for producing the specifiable torque value (T_Des) by means of a connectable electrical machine (120), b.) specifying a test signal (Sx_Test) (420) and superimposing the test signal (Sx_Test) on the current vector (Ix_V), c.) capturing (430), by means of a sensor (130), a response signal (Sx_Antw) resulting from the superimposing, e.) determining (450) a calibrated current vector (I_Vk) according to the evaluation of the response signal (Sx_Antw).

Claims

1. A method (400) for calibrating a control of an electrical machine (120) for a specifiable torque value (T_Des), wherein the electrical machine (120) is operated using a field-oriented control, the method comprising the following steps: a.) specifying a current vector (Ix_v) (410) to generate the specifiable torque value (T_Des) by means of a connectable electrical machine (120), wherein the current vector (Ix_v) has a length (1_s) and a direction (Ix_a) as parameters, b.) specifying a test signal (Sx_Test) (420) and superimposing the current vector (Ix_v) with the test signal (Sx_Test), c.) capturing (430) a response signal (Sx_Antw) resulting from the superposition by means of a sensor (130), d.) evaluating (440) the response signal (Sx_Antw), e.) determining (450) a calibrated current vector (I_Vk) as a function of the evaluation of the response signal (Sx_Antw), f.) operating (460) the control of the electrical machine (120) for the specifiable torque value (T_Des) by means of specifying the calibrated current vector (I_Vk).

2. The method as claimed in claim 1, wherein the test signal (Sx_Test) has a length (S_s) and a direction (Sx_a), wherein the direction (Sx_a) is aligned orthogonally to the current vector (Ix_V), and the test signal (Sx_Test) oscillates on both sides of the current vector (Ix_V).

3. The method as claimed in claim 1, wherein steps a.) to d.) are repeated at least twice, wherein the direction (Ix_a) of the current vector (Ix_V) is specified changed in each case by a specifiable absolute value (Ix_a_Delta), wherein upon the evaluation of the response signals (Sx_Antw) according to step d.), the captured response signals (Sx_Antw) are compared and a gradient or a minimum of the captured response signals (Sx_Antw) is ascertained.

4. The method as claimed in claim 3, wherein the direction (Ix_a) of the current vector (Ix_V) is specified in each case by a predefinable absolute value (Ix_a_Delta) in the positive and negative direction of the last specified current vector (Ix_V) or is specified in each case in the positive or negative direction of the last specified current vector (Ix_V).

5. The method as claimed in claim 4, wherein according to step e.), the calibrated current vector (I_Vk) is specified in that the parameters of the specified current vector (Ix_V), the captured response signal (Sx_Antw) of which is minimal, are specified for the calibrated current vector (I_Vk).

6. (canceled) .

7. A non-transitory, computer-readable medium containing instructions that when executed by a computer, cause the computer to control of an electrical machine (120) for a specifiable torque value (T_Des), wherein the electrical machine (120) is operated using a field- oriented control, by: a.) specifying a current vector (Ix_v) (410) to generate the specifiable torque value (T_Des) by means of a connectable electrical machine (120), wherein the current vector (Ix_v) has a length (1_s) and a direction (Ix_a) as parameters, b.) specifying a test signal (Sx Test) (420) and superimposing the current vector (Ix v) with the test signal (Sx_Test), c.) capturing (430) a response signal (Sx_Antw) resulting from the superposition by means of a sensor (130), d.) evaluating (440) the response signal (Sx_Antw), e.) determining (450) a calibrated current vector (I_Vk) as a function of the evaluation of the response signal (Sx_Antw), f.) operating (460) the control of the electrical machine (120) for the specifiable torque value (T_Des) by means of specifying the calibrated current vector (I_Vk).

8. A device (100) for calibrating a control (110) of an electrical machine (120), having a sensor (130), having a circuit carrier (150), wherein the circuit carrier has a test signal generator (160) and a computing unit (170), wherein the device is configured to a.) specify a current vector (Ix_v) (410) to generate the specifiable torque value (T_Des) by means of a connectable electrical machine (120), wherein the current vector (Ix_v) has a length (1_s) and a direction (Ix_a) as parameters, b.) specify a test signal (Sx_Test) (420) and superimposing the current vector (Ix_v) with the test signal (Sx_Test), c.) capture (430) a response signal (Sx_Antw) resulting from the superposition by means of a sensor (130), d.) evaluate (440) the response signal (Sx_Antw), e.) determine (450) a calibrated current vector (I_Vk) as a function of the evaluation of the response signal (Sx_Antw), and f.) operate (460) the control of the electrical machine (120) for the specifiable torque value (T_Des) by means of specifying the calibrated current vector (I_Vk).

9. The device as claimed in claim 8, wherein the sensor (130) is mechanically fixedly connected to the electrical machine (120) or the sensor (130) is fixedly attached to the circuit carrier (150) and the circuit carrier (150) is fixedly integrated in or on the electrical machine (120).

10. The device as claimed in claim 9, wherein the sensor (130) is a microphone, an acceleration sensor or structure-borne sound sensor or a speed sensor.

11. An electrical drive system (200) having an electrical machine (120) and a device (100) as claimed in claim 8.

12. A vehicle (300) having an electrical drive system (200) as claimed in claim 11.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further features and advantages of embodiments of the invention result from the following description with reference to the appended drawings.

[0038] The invention is explained in more detail hereinafter on the basis of several figures, in the figures:

[0039] FIG. 1 shows a schematic representation of a device for calibrating a control of an electrical machine,

[0040] FIG. 2 shows a diagram of the dq current plane with plotted iso-torque lines for application of a field-oriented control,

[0041] FIG. 3 shows a schematically illustrated vehicle having a drivetrain,

[0042] FIG. 4 shows a schematically illustrated flow chart for a method for calibrating an offset angle of a field-oriented control of an electrical machine.

DETAILED DESCRIPTION

[0043] FIG. 1 shows a device 100 for calibrating a control 110 of an electrical machine 120. The device comprises a sensor 130, preferably a mechanical sensor having a mechanically rigid or fixed direct or indirect connection to the electrical machine 120. Furthermore, the device comprises a circuit carrier 150, wherein the circuit carrier has a test signal generator 160 and a computing unit 170. The control 110 is preferably integrated in an inverter 140, wherein the inverter comprises a power electronics unit 145, preferably a B6 bridge, for supplying the connectable machine 120 from a battery 155. Furthermore, the electrical drive system 200 having the device 100 and the electrical machine 120 is shown in FIG. 1.

[0044] FIG. 2 shows a diagram of the dq current plane with plotted iso-torque lines for application of a field-oriented control. Zero-frequency variables result within the rotating coordinate system in stationary operation of the electrical machine from the alternating variables, for example, the phase currents. In the d/q coordinate system, which rotates synchronously with the rotor flux and the d axis of which points in the direction of the rotor flux, a stator current is represented as the current vector Ix_v, which is characterized via its absolute value or its length 1_s and its direction Ix_a. This current vector Ix_v rotates synchronously with the rotating stator flux or rotor flux of the electrical machine. In this coordinate system, machine-specific lines T1, T2, T3, T_Des can be represented, along which the electrical machine emits a constant torque. A control of an electrical machine can access the parameters of these lines by means of characteristic maps or data which can be parameterized. By means of variation of the direction Ix_a of the current vector, and thus different id and iq components, the different operating points can be set on these lines. Three current vectors having equal length Is are represented by I1_v, I2_v, and I3_v, the directions Ix_a of which each differ by a specifiable absolute value Ix_a_Delta. The specifiable test signals S1_Test, S2_Test, S3_Test are shown orthogonally to these current vectors. It can be seen from the diagram that the oscillating test signals S1_Test and S3_Test intersect more iso- torque lines than the test signal S2_Test. Therefore, greater torque variations result from the superposition of the current vectors and the test signals S1_Test and S3_Test than upon the superposition of the current vector I2_v and the test signal S2_Test with a connected electrical machine. Correspondingly, in this example the parameters, preferably the direction, of the current vector I2_v is assumed for the calibrated current vector I_Vk.

[0045] FIG. 3 shows a schematically illustrated vehicle 300 having an electrical drive system 200. The drive system 200 comprises the device 100 for calibrating the control 110 of the electrical machine 120 in the inverter 140 and the electrical machine 210. The electrical drive system preferably comprises the battery 150.

[0046] FIG. 4 shows a schematic sequence of a method 400 for calibrating a control of an electrical machine 120 for a specifiable torque value T_Des. The method starts with step 405. The electrical machine 120 is operated using a field-oriented control. The method comprises the following steps:

[0047] a.) specifying a current vector Ix_v, 410 to generate the specifiable torque value T_Des by means of a connectable electrical machine 120, wherein the current vector Ix_v has a length 1_s and a direction Ix_a as parameters,

[0048] b.) specifying a test signal Sx_Test, 420 and superimposing the current vector Ix_v with the test signal Sx_Test,

[0049] c.) capturing 430 a response signal Sx_Antw resulting from the superposition by means of a sensor 130,

[0050] d.) evaluating 440 the response signal Sx_Antw,

[0051] e.) determining 450 a calibrated current vector I_Vk as a function of the evaluation of the response signal Sx_Antw,

[0052] f.) operating 460 the control of the electrical machine 120 for the specifiable torque value T_Des by means of specifying the calibrated current vector I_Vk. Steps a.) to d.) 410 — 440 are preferably repeated at least twice for the iterative approximation to the direction of the current vector Ix_v, at which a connected electrical machine 120 generates the maximum torque. The method ends with step 470.