Permanent magnet synchronous motor inductance calibration method and device and computer equipment

Abstract

The application relates to a permanent magnet synchronous motor inductance calibration method, device and computer equipment; for each calibration condition, target calibration data of a motor to be measured at a target current test point is measured in a first calibration period; the target calibration data comprises direct-axis voltage, quadrature-axis current and motor torque; zero-current cross-axis voltage of the motor to be measured at a zero-current test point is measured in a second calibration period continuous with the first calibration period; inductance calibration data of the motor to be measured at the calibration condition is calculated based on an inductance parameter model, the target calibration data and the zero-current cross-axis voltage; inductance calibration errors caused by resistance drift due to stator temperature change are effectively avoided; meanwhile, interference of permanent magnet flux linkage drift caused by rotor temperature change on inductance calibration is effectively inhibited; efficient, wide-temperature, high-precision inductance parameter calibration is realized without the need of accurate temperature control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a permanent magnet synchronous motor inductance calibration method and device and computer equipment. BACKGROUND

[0002] As a kind of nonlinear, strong coupling, multivariable complex control unit, permanent magnet synchronous motor presents the characteristics of nonlinear change in control process, with the change of direct-axis current, inductance is influenced by magnetic saturation effect, cross coupling effect etc., and the change of inductance will affect motor control performance. In the traditional inductance calibration technology, in order to accurately obtain the inductance value of motor at different operating points, the influence of stator and rotor temperature change on winding resistance and permanent magnet flux linkage must be considered in the calibration process. Traditional calibration method usually requires that the temperature of motor stator and rotor is strictly controlled in a small range, so as to reduce the measurement error caused by parameter drift, but this leads to long time and low efficiency in calibration process; If the temperature change is ignored, resistance and flux linkage are regarded as constant parameters, then the calibrated inductance value will be greatly deviated from the actual value, which will affect the control accuracy.

[0003] In the traditional technology, the temperature of motor stator and rotor must be strictly controlled in the calibration process, which leads to limited calibration temperature range, long calibration period and low efficiency. At present, there is no effective solution to this problem. SUMMARY

[0004] Therefore, it is necessary to provide a permanent magnet synchronous motor inductance calibration method, device and computer equipment to solve the above technical problems.

[0005] In a first aspect, the present application provides a permanent magnet synchronous motor inductance calibration method, which comprises:

[0006] For each calibration condition, the target calibration data of the motor to be tested at the target current test point is measured in the first calibration period; The target calibration data includes direct-axis voltage, quadrature-axis current and motor torque;

[0007] In the second calibration period continuous with the first calibration period, the zero current cross-axis voltage of the motor to be tested at the zero current test point is measured;

[0008] Based on the inductance parameter model, the target calibration data and the zero current cross-axis voltage, the inductance calibration data of the motor to be tested at the calibration condition is calculated.

[0009] In one of the embodiments, there is a corresponding target current test point for each calibration condition; The target current test point is located in the corresponding preset current limit circle of the motor to be tested; The target calibration data of the motor to be tested at the target current test point is measured in the first calibration period, which comprises:

[0010] In the first calibration period, the motor under test is controlled based on the target current test point;

[0011] In the case where the operating state of the motor under test reaches a preset stable condition, target calibration data of the motor under test at the target current test point is measured.

[0012] In one of the embodiments, the zero-current cross-axis voltage of the motor under test at the zero-current test point is measured in a second calibration period continuous with the first calibration period, including:

[0013] In the second calibration period, the motor under test is controlled based on the zero-current test point;

[0014] In the case where the operating state of the motor under test reaches a preset stable condition, the zero-current cross-axis voltage of the motor under test at the zero-current test point is measured.

[0015] In one of the embodiments, the method for constructing the inductance parameter model includes:

[0016] The motor torque model, the flux linkage model in the rotating coordinate system, and the voltage model in the rotating coordinate system are obtained;

[0017] Based on the direct-axis and quadrature-axis currents, the voltage model is subjected to variable reorganization processing to construct a differential voltage model;

[0018] The differential voltage model and the motor torque model are jointly solved to obtain an analytical solution of the direct-axis and quadrature-axis flux linkages;

[0019] The flux linkage model and the analytical solution of the direct-axis and quadrature-axis flux linkages are jointly solved to obtain an inductance parameter model; the inductance parameter model includes a direct-axis inductance parameter model and a cross-axis inductance parameter model.

[0020] In one of the embodiments, the method for constructing the differential voltage model based on the direct-axis and quadrature-axis currents includes:

[0021] Based on the direct-axis and quadrature-axis currents, the voltage model is subjected to equivalent processing to obtain a direct-axis equivalent voltage model and a cross-axis equivalent voltage model;

[0022] The direct-axis equivalent voltage model and the cross-axis equivalent voltage model are subjected to differential calculation to obtain a differential voltage model.

[0023] In one of the embodiments, the direct-axis and quadrature-axis currents include a direct-axis current and a quadrature-axis current; the voltage model includes a quadrature-axis voltage model and a direct-axis voltage model; and the equivalent processing of the voltage model based on the direct-axis and quadrature-axis currents includes:

[0024] equivalent processing of the quadrature-axis voltage model based on the direct-axis current to obtain a quadrature-axis equivalent voltage model;

[0025] equivalent processing of the direct-axis voltage model based on the quadrature-axis current to obtain a direct-axis equivalent voltage model.

[0026] In one of the embodiments, the calculation of the inductance calibration data of the motor under the calibration condition based on the inductance parameter model, the target calibration data and the zero-current quadrature-axis voltage includes:

[0027] the target permanent magnet flux under the calibration condition of the motor based on the voltage model in the rotating coordinate system and the zero-current quadrature-axis voltage;

[0028] the inductance calibration data of the motor under the calibration condition based on the inductance parameter model, the target calibration data and the target permanent magnet flux.

[0029] In one of the embodiments, the voltage model includes a quadrature-axis voltage model and a direct-axis voltage model; and the calculation of the target permanent magnet flux under the calibration condition of the motor based on the voltage model in the rotating coordinate system and the zero-current quadrature-axis voltage includes:

[0030] substituting the zero-current quadrature-axis voltage into the quadrature-axis voltage model to obtain a direct-axis flux under the calibration condition of the motor;

[0031] obtaining a direct-axis flux model in the rotating coordinate system;

[0032] substituting the direct-axis flux into the direct-axis flux model to obtain the target permanent magnet flux under the calibration condition of the motor.

[0033] In one of the embodiments, the calculation of the inductance calibration data of the motor under the calibration condition based on the inductance parameter model, the target calibration data and the target permanent magnet flux includes:

[0034] obtaining an operating state parameter corresponding to the motor;

[0035] solving the inductance parameter model based on the operation state parameter, the direct-axis voltage, the quadrature-axis voltage, the motor torque and the target permanent magnet flux linkage, to obtain inductance calibration data of the motor to be tested under the calibration condition;

[0036] The inductance calibration data comprises direct-axis inductance data and quadrature-axis inductance data.

[0037] In a second aspect, the application provides a permanent magnet synchronous motor inductance calibration device, which comprises:

[0038] A first measurement module is configured to measure target calibration data of the motor to be tested under a target current test point in a first calibration period for each calibration condition, wherein the target calibration data comprises direct-axis voltage, quadrature-axis voltage, direct-axis current, quadrature-axis current and motor torque.

[0039] A second measurement module is configured to measure zero-current quadrature-axis voltage of the motor to be tested under a zero-current test point in a second calibration period continuous with the first calibration period.

[0040] An inductance calculation module is configured to calculate inductance calibration data of the motor to be tested under the calibration condition based on an inductance parameter model, the target calibration data and the zero-current quadrature-axis voltage.

[0041] In a third aspect, the application provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method as described above when executing the computer program.

[0042] In a fourth aspect, the application provides a computer readable storage medium, which stores a computer program, and the computer program implements the steps of the method as described above when executed by a processor.

[0043] In a fifth aspect, the application provides a computer program product comprising a computer program, and the computer program implements the steps of the method as described above when executed by a processor.

[0044] The permanent magnet synchronous motor inductance calibration method, device and computer equipment measure target calibration data of the motor to be tested at a target current test point in a first calibration period for each calibration condition; the target calibration data includes direct-axis voltage, quadrature-axis voltage, direct-axis current, quadrature-axis current and motor torque; measure zero-current quadrature-axis voltage of the motor to be tested at a zero-current test point in a second calibration period continuous with the first calibration period; and calculate inductance calibration data of the motor to be tested at the calibration condition based on an inductance parameter model, the target calibration data and the zero-current quadrature-axis voltage. By setting the continuous first calibration period and the second calibration period at each calibration condition, the direct-axis voltage, the quadrature-axis voltage, the direct-axis current, the quadrature-axis current and the motor torque at the target current test point are collected in the first calibration period, and by using the inductance calibration method independent of the stator phase resistance as the input parameter, the inductance calibration error caused by the resistance drift due to the stator temperature change is effectively avoided; at the same time, the zero-current quadrature-axis voltage is measured at the zero-current test point in the second calibration period, which can effectively suppress the interference of the rotor temperature change on the inductance calibration. Based on this, efficient, wide temperature and high-precision inductance parameter calibration is realized without the need for accurate temperature control. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other related drawings can be obtained by those skilled in the art without creative labor.

[0046] Figure 1 A flowchart of the inductance calibration method of the permanent magnet synchronous motor in one embodiment;

[0047] Figure 2 A second quadrant diagram of the preset current limit circle in one embodiment;

[0048] Figure 3 A flowchart of the construction steps of the inductance parameter model in one embodiment;

[0049] Figure 4 A flowchart of the calculation steps of the inductance calibration data in one embodiment;

[0050] Figure 5 A structural block diagram of the inductance calibration device of the permanent magnet synchronous motor in one embodiment;

[0051] Figure 6 An internal structure diagram of the computer equipment in one embodiment. DETAILED DESCRIPTION

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0053] As a complex system characterized by nonlinearity, strong coupling, and multiple variables, the inductance characteristics of a permanent magnet synchronous motor undergo significant nonlinear changes during operation due to factors such as magnetic saturation and cross-coupling effects, as the direct axis (d-axis) and quadrature axis (q-axis) currents change. The accuracy of the inductance parameters directly affects the dynamic response and steady-state performance of the motor control system.

[0054] To accurately obtain the inductance value of a motor at different operating points, the influence of stator and rotor temperature changes on winding resistance and permanent magnet flux linkage must be considered during calibration. Traditional calibration methods typically require strict control of the motor's stator and rotor temperatures within a small range to reduce measurement errors caused by parameter drift, but this results in a time-consuming and inefficient calibration process. If temperature changes are ignored and resistance and flux linkage are treated as constant parameters, the calibrated inductance value will deviate significantly from the actual value, affecting control accuracy.

[0055] To address the aforementioned issues, this application proposes a method for calibrating the inductance of a permanent magnet synchronous motor. This method aims to reduce the impact of motor stator and rotor temperatures on inductance calibration, achieving high-efficiency, wide-temperature, and high-precision inductance parameter calibration without the need for precise temperature control.

[0056] In one embodiment, such as Figure 1 As shown, Figure 1 This is a flowchart illustrating a permanent magnet synchronous motor inductor calibration method in one embodiment; the permanent magnet synchronous motor inductor calibration method includes the following steps:

[0057] Step S101: For each calibration condition, within the first calibration period, measure the target calibration data of the motor under test at the target current test point.

[0058] Each calibration condition has a corresponding target current test point; the target current test point is used to apply a specific right-angle shaft current value to the motor under test; the target current test point is located within the preset current limit circle corresponding to the motor under test to ensure that it does not exceed the safe operating boundary of the motor under test.

[0059] The preset current limit circle refers to the current operating boundary defined in the orthogonal axis current coordinate system, used to limit the motor's operation within a safe current range. The preset current limit circle is related to the driving performance of the motor under test and is not specifically limited here. In an exemplary embodiment, a partial schematic diagram of the preset current limit circle is shown below. Figure 2as shown, Figure 2 The black dots in the current limit circle represent current test points. It can be understood that each current test point can be used as a target current test point. In actual calibration, the corresponding current test point is selected as the target current test point according to the specific calibration requirement, which is not limited here.

[0060] It should be noted that the target current test point is a non-zero current test point, that is, the direct-axis current value and the quadrature-axis current value corresponding to the target current test point are both not 0.

[0061] It can be understood that the determination method of the current test point can be, but is not limited to, uniformly distributing points in the preset current limit circle by using a fixed direct-quadrature axis current step, or non-uniformly distributing points in the preset current limit circle according to the key area of the motor control strategy. It can be understood that the determination method of the current test point needs to be selected according to the actual requirement, which is not limited here.

[0062] The first calibration period refers to the time period when the motor under test runs at the target current test point in each calibration condition.

[0063] The target calibration data includes direct-quadrature axis voltage, direct-quadrature axis current and motor torque. The direct-quadrature axis voltage includes direct-axis voltage and quadrature-axis voltage. The direct-quadrature axis current includes direct-axis current and quadrature-axis current. It should be noted that the direct-quadrature axis voltage, the direct-quadrature axis current and the motor torque are all input parameters of the inductance parameter model.

[0064] In step S102, the zero-current quadrature-axis voltage of the motor under test at the zero-current test point is measured in the second calibration period continuous with the first calibration period.

[0065] The second calibration period refers to the continuous time period immediately after the first calibration period. The zero-current quadrature-axis voltage refers to the quadrature-axis voltage measured at the zero-current test point, that is, the quadrature-axis voltage measured under the test condition that the direct-axis current and the quadrature-axis current are both 0.

[0066] It should be noted that the specific duration of the first calibration period and the second calibration period should ensure that the motor under test can reach steady state operation at the target current test point and the zero-current test point, and at the same time, the duration of the first calibration period and the second calibration period should be as short as possible to suppress the temperature rise accumulation of the motor stator and rotor, so that the change of the thermal state in the entire calibration process is within the allowable range, thereby ensuring the consistency of the permanent magnet flux linkage between the first calibration period and the second calibration period.

[0067] It can be understood that by setting the first calibration period and the second calibration period to be executed continuously, the collection of the target calibration data and the zero-current cross-axis voltage can be completed in a time window in which the motor thermal state changes little, so that the stator and rotor temperatures in the two periods are approximately consistent; under this condition, it can be reasonably presumed that the permanent magnet flux linkage at the zero-current test point in the second calibration period is the same as the permanent magnet flux linkage at the target current test point in the first calibration time. Further, by measuring the zero-current cross-axis voltage at the zero-current test point, the permanent magnet flux linkage under the current calibration condition can be calculated, which not only avoids introducing the stator phase resistance in the entire calibration process, but also avoids introducing the inductance calibration error caused by the drift of the permanent magnet flux linkage due to the change of the rotor temperature.

[0068] In step S103, the inductance calibration data of the motor to be tested under the calibration condition is calculated based on the inductance parameter model, the target calibration data, and the zero-current cross-axis voltage.

[0069] The inductance parameter model refers to a mathematical model for describing the relationship between the motor inductance and the direct-axis voltage, the quadrature-axis voltage, the direct-axis current, the quadrature-axis current, and the motor torque. The inductance parameter model includes a direct-axis inductance parameter model and a quadrature-axis inductance parameter model. The inductance calibration data includes direct-axis inductance data and quadrature-axis inductance data.

[0070] It should be noted that the inductance parameter model of the present application does not rely on the stator phase resistance as an input parameter, which ensures that the inductance parameter solving process fundamentally avoids the calibration error caused by the drift of the winding resistance due to the change of the stator temperature.

[0071] For example, a dynamometer platform is established using a dynamometer, which includes a test motor and a motor to be tested. In the inductance calibration process, a field-oriented controlled motor is used, and the motor to be tested is driven by the test motor to a certain constant speed, and the speed range can be set to 0.2-1 times the rated speed of the motor to be tested. Further, for each calibration condition, a target current test point corresponding to the calibration condition is selected, and a corresponding control instruction is issued to the motor to be tested based on the target current test point on the dynamometer platform, so as to measure the direct-axis voltage, the quadrature-axis voltage, the direct-axis current, the quadrature-axis current, and the motor torque of the motor to be tested at the target current test point in the first calibration period, and take the direct-axis voltage, the quadrature-axis voltage, the direct-axis current, the quadrature-axis current, and the motor torque as the target calibration data. After the measurement of the target calibration data is completed, a corresponding control instruction is issued to the motor to be tested based on the zero-current test point on the dynamometer platform in the second calibration period which is continuous with the first calibration period, so as to measure the zero-current cross-axis voltage of the motor to be tested at the zero-current test point. Further, the target calibration data and the zero-current cross-axis voltage are taken as the input parameters of the inductance parameter model, and the direct-axis inductance calibration data and the quadrature-axis inductance calibration data of the motor to be tested under the calibration condition are calculated based on the inductance parameter model.

[0072] In the embodiment, by setting continuous first calibration period and second calibration period under each calibration condition, the quadrature axis voltage, the direct axis current and the motor torque under the target current test point are collected in the first calibration period, and by using the inductance calibration method which does not depend on the stator phase resistance as the input parameter, the inductance calibration error caused by the resistance drift due to the stator temperature change is effectively avoided; at the same time, the zero current quadrature axis voltage is measured under the zero current test point in the second calibration period, which can effectively suppress the interference of the rotor temperature change on the inductance calibration. Based on this, without the need for accurate temperature control, efficient, wide temperature and high-precision inductance parameter calibration is realized.

[0073] In one embodiment, in the first calibration period, the target calibration data of the motor to be tested at the target current test point is measured, including the following steps:

[0074] Step 1, in the first calibration period, the current control of the motor to be tested is based on the target current test point.

[0075] Step 2, in the case that the operating state of the motor to be tested reaches the preset stable condition, the target calibration data of the motor to be tested at the target current test point is measured.

[0076] The preset stable condition is used to ensure that the motor to be tested has entered a steady state operation, that is, the fluctuations of the key parameters such as the direct axis current, the quadrature axis current, the voltage, the speed and the torque are within the allowable error range, so as to ensure the accuracy of the collected data.

[0077] It should be noted that the preset stable condition needs to be reasonably set according to the actual performance parameters of the motor to be tested, which is not limited specifically herein.

[0078] For example, based on the target current test point, the corresponding control instruction is issued under the dynamometer platform to control the current of the motor to be tested, and after the operating state of the motor to be tested reaches the preset stable condition, the target calibration data of the motor to be tested under the operating condition is recorded for several times within Ts time, that is, the d-axis voltage u d , the q-axis voltage u q , the d-axis current i d , the q-axis current i q , and the motor torque T e ; wherein the motor torque can be detected by a torque sensor, but is not limited thereto. It should be noted that the Ts time is less than the first calibration period and is included in the first calibration period. The value of the Ts time should be as small as possible, for example, less than or equal to 1s.

[0079] In this embodiment, during the first calibration period, the current of the motor under test is controlled based on the target current test point. Before measurement, it is determined whether the motor under test has reached the preset stability condition. After the preset stability condition is met, the target calibration data of the motor under test at the target current test point is measured. This ensures the safety of the inductor calibration process and the accuracy and reliability of data acquisition, laying a data foundation for the calibration of inductor parameters under calibration conditions.

[0080] In one embodiment, measuring the zero-current quadrature-axis voltage of the motor under test at a zero-current test point during a second calibration period that is continuous with the first calibration period includes the following steps:

[0081] Step 1: During the second calibration period, perform current control on the motor under test based on the zero current test point.

[0082] Step 2: When the motor under test reaches the preset stable operating conditions, measure the zero-current quadrature-axis voltage of the motor under test at the zero-current test point.

[0083] For example, immediately after the target calibration data measurement is completed, in the second calibration period that is consecutive to the first calibration period, based on the zero-current test point, the corresponding control command is issued on the dynamometer platform to control the current of the motor under test. After the operating state of the motor under test reaches the preset stable condition, the zero-current quadrature-axis voltage, i.e., the q-axis voltage u, is quickly and continuously recorded several times within a time Ts. q It should be noted that the Ts time is shorter than the second calibration period and is included within the second calibration period. The value of Ts should be as small as possible, for example, less than or equal to 1 second.

[0084] In this embodiment, during the second calibration period, which is continuous with the first calibration period, the current of the motor under test is controlled based on the zero-current test point. Before measurement, it is determined whether the motor under test has reached the preset stability condition. After the preset stability condition is met, the zero-current quadrature-axis voltage of the motor under test at the zero-current test point is measured. This ensures the safety of the inductance calibration process and the accuracy and reliability of data acquisition. It lays the data foundation for the accurate calculation of the permanent magnet flux linkage under the calibration conditions and avoids the influence of rotor temperature changes on the inductance calibration results.

[0085] In one embodiment, such as Figure 3 As shown, Figure 3 This is a flowchart illustrating the steps involved in constructing an inductor parameter model in one embodiment; the method for constructing the inductor parameter model includes the following steps:

[0086] Step S301: Obtain the motor torque model, the flux linkage model in the rotating coordinate system, and the voltage model in the rotating coordinate system.

[0087] Wherein, the mathematical expression of the motor torque model is shown as formula (1) :

[0088] (1) ;

[0089] Wherein, is the motor torque; is the d-axis flux, i.e. the direct-axis flux; is the q-axis flux, i.e. the quadrature-axis flux; is the motor pole pair number; i d is the d-axis current, i.e. the direct-axis current; i q is the q-axis current, i.e. the quadrature-axis current.

[0090] Wherein, the mathematical expression of the flux model in the rotating coordinate system is shown as formula (2) :

[0091] (2) ;

[0092] Wherein, is the d-axis flux, i.e. the direct-axis flux; is the q-axis flux, i.e. the quadrature-axis flux; i d is the d-axis current, i.e. the direct-axis current; i q is the q-axis current, i.e. the quadrature-axis current; is the q-axis inductance, i.e. the quadrature-axis inductance; is the d-axis inductance, i.e. the direct-axis inductance; is the permanent magnet flux.

[0093] Wherein, the mathematical expression of the voltage model in the rotating coordinate system is shown as formula (3), and it is necessary to note that the voltage model in the rotating coordinate system is the steady-state voltage model.

[0094] (3) ;

[0095] Wherein, is the electrical angular velocity, and its calculation formula is ; u d is the d-axis voltage, i.e. the direct-axis voltage; u q is the q-axis voltage, i.e. the quadrature-axis voltage; R s is the stator phase resistance; i d is the d-axis current, i.e. the direct-axis current; i q is the q-axis current, i.e. the quadrature-axis current; is the d-axis flux, i.e. the direct-axis flux; is the q-axis flux, i.e. the quadrature-axis flux; n r is the motor speed; n p is the motor pole pair number.

[0096] In step S302, based on the direct-axis and quadrature-axis currents, variable reorganization processing is performed on the voltage model to construct a differential voltage model.

[0097] The direct-axis and quadrature-axis currents include a direct-axis current and a quadrature-axis current.

[0098] The differential voltage model is used to eliminate the stator phase resistance term to avoid the influence of resistance drift caused by stator temperature change on inductance calibration.

[0099] It should be noted that according to the voltage model (i.e., the steady-state voltage model) shown in formula (3), it can be concluded that the voltage model contains a stator phase resistance R s term; by constructing a differential voltage model, the stator phase resistance R s term can be eliminated, so that the inductance calibration process is independent of the stator phase resistance, thereby suppressing the error caused by the stator temperature change.

[0100] The purpose of the variable reorganization processing on the voltage model is to eliminate the easily disturbed parameter term (i.e., the stator phase resistance) by reorganizing the variable relationship in the voltage model, to construct a new form model more suitable for inductance parameter calibration, thereby improving the robustness and accuracy of inductance calibration. That is, the terms in the voltage model are recombined, so that the term containing the stator phase resistance R s is canceled in the new equation, thereby constructing a differential voltage model independent of the stator phase resistance R s , to avoid the resistance drift error caused by the stator temperature change.

[0101] In an exemplary embodiment, the variable reorganization processing can include, but is not limited to, equivalent processing and differential processing. Based on the direct-axis and quadrature-axis currents, variable reorganization processing is performed on the voltage model to construct a differential voltage model, including the following steps:

[0102] Step 1, based on the direct-axis and quadrature-axis currents, equivalent processing is performed on the voltage model to obtain a direct-axis equivalent voltage model and a quadrature-axis equivalent voltage model.

[0103] Step 2, differential calculation is performed on the direct-axis equivalent voltage model and the quadrature-axis equivalent voltage model to obtain a differential voltage model.

[0104] The direct-axis equivalent voltage model and the quadrature-axis equivalent voltage model have the same parameter term, and the same parameter term contains the stator phase resistance R s . The purpose of the differential calculation on the direct-axis equivalent voltage model and the quadrature-axis equivalent voltage model is to eliminate the same parameter term, thereby completely eliminating the term containing the stator phase resistance Rs to obtain the corresponding differential voltage model.

[0105] In one exemplary embodiment, step 1 is based on the direct-axis current, equivalent processing is performed on the voltage model to obtain a direct-axis equivalent voltage model and a quadrature-axis equivalent voltage model, including the following steps:

[0106] Step 1.1, based on the direct-axis current, equivalent processing is performed on the quadrature-axis voltage model to obtain a quadrature-axis equivalent voltage model.

[0107] Step 1.2, based on the quadrature-axis current, equivalent processing is performed on the direct-axis voltage model to obtain a direct-axis equivalent voltage model.

[0108] Exemplarily, based on formula (3), the quadrature-axis voltage model is ; the direct-axis voltage model is ; based on the direct-axis current , equivalent processing is performed on the quadrature-axis voltage model to obtain a quadrature-axis equivalent voltage model ; based on the quadrature-axis current , equivalent processing is performed on the direct-axis voltage model to obtain a direct-axis equivalent voltage model . Further, it can be concluded that the same parameter term of the direct-axis equivalent voltage model and the quadrature-axis equivalent voltage model is .

[0109] Further, difference calculation is performed on the direct-axis equivalent voltage model and the quadrature-axis equivalent voltage model to obtain a difference voltage model as shown in formula (4).

[0110] (4)

[0111] wherein, is the electrical angular velocity, and the calculation formula is ; u d is the d-axis voltage, i.e., the direct-axis voltage; u q is the q-axis voltage, i.e., the quadrature-axis voltage; i d is the d-axis current, i.e., the direct-axis current; i q is the q-axis current, i.e., the quadrature-axis current; is the d-axis flux linkage, i.e., the direct-axis flux linkage; is the q-axis flux linkage, i.e., the quadrature-axis flux linkage; n r is the motor speed; n p is the motor pole pair number.

[0112] Step S303, joint solving processing is performed on the difference voltage model and the motor torque model to obtain a direct-quadrature-axis flux linkage analytical solution.

[0113] wherein, the direct-quadrature-axis flux linkage analytical solution includes a direct-axis flux linkage analytical solution and a quadrature-axis flux linkage analytical solution. It can be understood that the direct-quadrature-axis flux linkage analytical solution represents an explicit expression of the direct-quadrature-axis flux linkage.

[0114] Exemplarily, the differential voltage model and the motor torque model are jointly solved, that is, formula (4) and formula (2) are solved simultaneously, and the analytical solution of the direct-axis and quadrature-axis fluxes is as shown in formula (5).

[0115] (5)

[0116] wherein, is the analytical solution of the direct-axis flux; is the analytical solution of the quadrature-axis flux; is the electrical angular velocity, and the calculation formula is ;u d is the d-axis voltage, that is, the direct-axis voltage; u q is the q-axis voltage, that is, the quadrature-axis voltage; i d is the d-axis current, that is, the direct-axis current; i q is the q-axis current, that is, the quadrature-axis current; is the d-axis flux, that is, the direct-axis flux; is the q-axis flux, that is, the quadrature-axis flux; n r is the motor speed; n p is the motor pole pair number; is the motor torque.

[0117] In step S304, the flux model and the analytical solution of the direct-axis and quadrature-axis fluxes are jointly solved to obtain an inductance parameter model.

[0118] wherein, the inductance parameter model includes a direct-axis inductance parameter model and a quadrature-axis inductance parameter model.

[0119] Exemplarily, the flux model and the analytical solution of the direct-axis and quadrature-axis fluxes are jointly solved, that is, formula (2) and formula (5) are solved simultaneously, and the inductance parameter model is as shown in formula (6).

[0120] (6)

[0121] wherein, is the direct-axis inductance parameter model; is the quadrature-axis inductance parameter model; is the electrical angular velocity, and the calculation formula is ;u d is the d-axis voltage, that is, the direct-axis voltage; u q is the q-axis voltage, that is, the quadrature-axis voltage; i d is the d-axis current, that is, the direct-axis current; i q is the q-axis current, that is, the quadrature-axis current; is the d-axis flux, that is, the direct-axis flux; is the q-axis flux, that is, the quadrature-axis flux; n r is the motor speed; n p is the motor pole pair number; is the motor torque; is the permanent magnet flux linkage.

[0122] It should be noted that when calculating the inductance calibration data based on the inductance parameter model shown in formula (6), the quadrature-axis voltage measured in the first calibration period is substituted into u q in formula (6), and the zero-current quadrature-axis voltage measured in the second calibration period is used to calculate the permanent magnet flux linkage .

[0123] It should be noted that by setting the first calibration period and the second calibration period to be executed continuously, the collection of the target calibration data and the zero-current quadrature-axis voltage can be completed within a time window in which the motor thermal state changes little, so that the stator and rotor temperatures under the two periods are approximately consistent. Under this condition, it can be reasonably assumed that the permanent magnet flux linkage at the zero-current test point in the second calibration period is the same as the permanent magnet flux linkage at the target current test point in the first calibration time. Further, by measuring the zero-current quadrature-axis voltage at the zero-current test point, the permanent magnet flux linkage under the current calibration condition can be calculated. Based on this, not only can the stator phase resistance be avoided in the entire calibration process, but also the inductance calibration error caused by the drift of the permanent magnet flux linkage due to the change of the rotor temperature can be avoided.

[0124] It can be understood that the direct-axis and quadrature-axis currents corresponding to the zero-current test point are both 0. By substituting the zero-current test point and the zero-current quadrature-axis voltage into the quadrature-axis voltage model and the direct-axis flux linkage model , the permanent magnet flux linkage under the current calibration condition can be calculated.

[0125] Further, it should be noted that the inductance parameter model, i.e. formula (6), cannot satisfy the calculation of the direct-axis inductance when is 0A, and the calculation of the quadrature-axis inductance when is 0A. The fundamental reason is that there are terms with or as the denominator in the inductance parameter model, resulting in the failure of the mathematical expression under the zero-current condition. However, since the cross-coupling effect of the motor is weak and the inductance changes smoothly under the small current condition of = = 0A, that is, the inductance does not change significantly at small currents. Based on this characteristic, the inductance calibration results of adjacent non-zero current test points can be reasonably replaced. For example, when the inductance calibration data of the zero-current test point is needed, the inductance calibration data calculated at the direct-axis and quadrature-axis currents of 4A (or other currents close to but not zero) can be used as an approximate value to realize the integrity of the inductance mapping in the full current range.

[0126] In this embodiment, based on the right-angle axis current, the voltage model undergoes variable recombination to construct a differential voltage model, eliminating stator phase resistance-related terms. This eliminates the need for stator phase resistance parameters during inductor calibration, fundamentally avoiding the resistance drift caused by stator temperature changes. Furthermore, by jointly solving the differential voltage model and the motor torque model, an analytical solution for the right-angle axis flux linkage is obtained. Then, the flux linkage model is jointly solved with the analytical solution for the right-angle axis flux linkage to construct an inductor parameter model, achieving an explicit analytical solution for the inductance value. Based on this, strict temperature control is unnecessary during actual calibration, effectively shortening the calibration cycle and improving calibration efficiency. This lays the foundation for achieving wide-temperature, high-precision, and high-efficiency inductor calibration.

[0127] In one embodiment, such as Figure 4 As shown, Figure 4 This is a flowchart illustrating the calculation steps for inductance calibration data in one embodiment. Based on the inductance parameter model, target calibration data, and zero-current quadrature-axis voltage, the inductance calibration data of the motor under test under calibration conditions is calculated, including the following steps:

[0128] Step S401: Based on the voltage model in the rotating coordinate system and the zero-current quadrature-axis voltage, calculate the target permanent magnet flux linkage of the motor under test under calibration conditions.

[0129] It should be noted that the stator and rotor temperatures are approximately the same during the first and second calibration periods. Under these conditions, it can be reasonably estimated that the permanent magnet flux linkage at the zero-current test point during the second calibration period is the same as that at the target current test point during the first calibration period. Based on this, this application selects to measure the zero-current quadrature-axis voltage at the zero-current test point and calculate the target permanent magnet flux linkage of the motor under test under calibration conditions to ensure that the inductance calibration error caused by the drift of the permanent magnet flux linkage due to rotor temperature changes can be effectively avoided, while also avoiding the introduction of stator phase resistance.

[0130] In an exemplary embodiment, based on the voltage model in a rotating coordinate system and the zero-current quadrature-axis voltage, the target permanent magnet flux linkage of the motor under test under calibration conditions is calculated, including the following steps:

[0131] Step 1: Substitute the zero-current quadrature-axis voltage into the quadrature-axis voltage model to obtain the direct-axis flux linkage of the motor under test under calibration conditions.

[0132] Step 2: Obtain the direct-axis flux linkage model in the rotating coordinate system.

[0133] Step 3: Substitute the direct-axis flux linkage into the direct-axis flux linkage model to obtain the target permanent magnet flux linkage of the motor under test under calibration conditions.

[0134] For example, the zero-current quadrature-axis voltage and the zero-current test point ( ) Substitute the quadrature axis voltage model , to obtain the direct axis flux linkage of the motor to be tested under the calibration condition . Further, substitute the direct axis flux linkage into the direct axis flux linkage model , wherein , to obtain the target permanent magnet flux linkage of the motor to be tested under the calibration condition .

[0135] Step S402, based on the inductance parameter model, the target calibration data and the target permanent magnet flux linkage, calculate the inductance calibration data of the motor to be tested under the calibration condition.

[0136] In an exemplary embodiment, based on the inductance parameter model, the target calibration data and the target permanent magnet flux linkage, the inductance calibration data of the motor to be tested under the calibration condition is calculated, comprising the following steps:

[0137] Step 1, obtain the running state parameters corresponding to the motor to be tested.

[0138] Wherein, the running state parameters at least include motor speed, motor pole pair number; it can be understood that the running state parameters are all known and directly obtainable data.

[0139] Step 2, based on the running state parameters, the direct and quadrature axis voltages, the direct and quadrature axis currents, the motor torque and the target permanent magnet flux linkage, the inductance parameter model is solved to obtain the inductance calibration data of the motor to be tested under the calibration condition.

[0140] Wherein, the inductance calibration data includes direct axis inductance data and quadrature axis inductance data.

[0141] Exemplarily, the running state parameters (such as motor speed, motor pole pair number) corresponding to the motor to be tested are obtained, and the running state parameters, the direct and quadrature axis voltages, the direct and quadrature axis currents, the motor torque and the target permanent magnet flux linkage are substituted into the inductance parameter model, i.e. the above formula (6) is solved to obtain the direct axis inductance data and the quadrature axis inductance data of the motor to be tested under the calibration condition.

[0142] In this embodiment, based on the zero current quadrature axis voltage under the zero current test point, the target permanent magnet flux of the motor to be tested under the calibration condition is calculated, which can effectively avoid the inductance calibration error introduced by the permanent magnet flux linkage drift caused by the rotor temperature change, and at the same time can avoid introducing the stator phase resistance. Further, based on the running state parameters, the direct and quadrature axis voltages, the direct and quadrature axis currents, the motor torque and the target permanent magnet flux linkage, the inductance parameter model is solved to obtain the inductance calibration data of the motor to be tested under the calibration condition, which realizes efficient, wide temperature and high precision inductance parameter calibration without the need for accurate temperature control.

[0143] In one specific embodiment, the permanent magnet synchronous motor inductance calibration method of the present application is actually tested, and the evaluation environment is as follows:

[0144] This example takes a 10-pole permanent magnet synchronous motor as an example. The motor rated speed is 2500 rpm, the current limit circle is 56 A, the current calibration step is 4 A, and the inductance calibration is carried out at 1000 rpm. The motor stator temperature range is 25-105℃, and the rotor temperature is not measured or controlled.

[0145] As shown in Table 1, taking the target current test point corresponding to the direct-axis current i d = -8A and the quadrature-axis current i q = 20A as an example, in the first calibration period, the current control is carried out on the motor to be tested based on the target current test point, and after the operating state of the motor to be tested reaches the preset stable condition, the target calibration data is recorded by continuous sampling for 4 times (recorded in order No. 1-No. 4). The target calibration data includes: d-axis voltage u d , q-axis voltage u q , d-axis current i d , q-axis current i q , and motor torque T e detected by the torque sensor; in the second calibration period continuous with the first calibration period, the current control is carried out on the motor to be tested based on the zero current test point, and after the operating state of the motor to be tested reaches the preset stable condition, the zero current quadrature-axis voltage, i.e. q-axis voltage u q , is recorded by continuous sampling for 4 times (recorded in order No. 5-No. 8).

[0146] In Table 1, i d is the direct-axis current, i q is the quadrature-axis current, u d is the direct-axis voltage, and u q is the quadrature-axis voltage. T rq is the measured motor torque.

[0147] Table 1

[0148]

[0149] According to the inductance parameter model, i.e. formula (6), the direct-axis inductance L d = 60.15uH and the quadrature-axis inductance L q = 57.94uH are calculated.

[0150] Further, based on the permanent magnet synchronous motor inductance calibration method described in the above embodiment, the test data (including target calibration data and zero current cross-axis voltage) under each calibration condition is batch processed to obtain the direct and quadrature axis inductance calibration data shown in Table 2 and Table 3. Among them, Table 2 is the d-axis inductance value calculated by the method of the application; Table 3 is the q-axis inductance value calculated by the method of the application.

[0151] Table 2

[0152]

[0153] Table 3

[0154]

[0155] Further, in order to verify the effectiveness of the permanent magnet synchronous motor inductance calibration method of the application, the following two groups of control experiments are set:

[0156] Control experiment one:

[0157] For the experimental data of the motor stator and rotor temperature in the wide temperature range in the above Table 2 and Table 3, according to the traditional method, i.e. formula (3), the instrument is used to test the phase resistance R s =50.22mΩ, the permanent magnet flux linkage =4.751mT value as a constant at 25℃ room temperature before experimental test, the calculation results are shown in Table 4 and Table 5, wherein Table 4 is the d-axis inductance value calculated by the traditional scheme (25~105℃ stator temperature); Table 5 is the q-axis inductance value calculated by the traditional scheme (25~105℃ stator temperature).

[0158] Table 4

[0159]

[0160] Table 5

[0161]

[0162] In control experiment one, the average value of L d is 3.02uH, and the average value of L d calculated by the method of the application is 2.79uH. q q

[0163] Control experiment two:

[0164] ​​The motor stator temperature is controlled between 25 and 55°C. Since the rotor temperature cannot be directly measured, inductance calibration is indirectly ensured by repeatedly measuring the back electromotive force during calibration intervals, ensuring the deviation does not exceed ±2% of the initial measurement. The inductance is then recalibrated under conditions where the rotor temperature variation is minimal. Before calibration begins, the motor windings are heated to the 25-45°C range, and the phase resistance R is measured using a digital bridge. s= 50.42mΩ; The permanent magnet flux linkage was calculated by the dynamometer based on the back electromotive force of the test motor. =4.75mT. According to formula (3), the resistance and magnetic flux are substituted into the formula as constants, and the calculation results are shown in Table 6 and Table 7. Table 6 is the d-axis inductance value calculated by the traditional scheme (stator temperature 25~55℃); Table 7 is the q-axis inductance value calculated by the traditional scheme (stator temperature 25~55℃).

[0165] Table 6

[0166]

[0167] Table 7

[0168]

[0169] In control experiment two, L d The average value and L calculated by the method described in this application d The error of the average value is 1.91uH, L q The average value and L calculated by the method described in this application q The average error is 1.44uH.

[0170] The above experimental results confirm that the inductance calibration method of the permanent magnet synchronous motor in this application has a smaller difference in inductance results compared with the conventional calibration scheme of the control group two (25~55℃ stator and rotor temperature). However, the calibration process of the control group two is more complicated and takes longer.

[0171] Compared with the conventional calibration scheme of 25~105℃ stator and rotor temperature, the inductance calibration method of permanent magnet synchronous motor in this application will cause a larger error in the calibration inductance value.

[0172] In summary, the application can calibrate in a wide temperature range without strict control of the temperature of the stator and rotor of the motor, greatly reducing the workload while ensuring the accuracy of the inductance calibration, and combining work efficiency and calibration accuracy. It can be understood that the stator resistance variable is directly eliminated in the inductance parameter model of the application, avoiding the problem of inductance calculation deviation caused by the change of stator resistance due to temperature change; at the same time, since the rotor temperature is difficult to detect, the application sets a continuous first calibration period and a second calibration period, and immediately resets the current to zero and records the zero-current cross-axis voltage after each calibration of a target current test point. The target permanent magnet flux value can be calculated according to the voltage model and the flux linkage model, so as to avoid the influence of rotor temperature on the permanent magnet flux.

[0173] It should be understood that, although each step in the flowchart involved in each embodiment as described above is displayed in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in each embodiment as described above can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least part of other steps or steps or stages in other steps.

[0174] Based on the same inventive concept, the application also provides a permanent magnet synchronous motor inductance calibration device for implementing the above-mentioned permanent magnet synchronous motor inductance calibration method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more permanent magnet synchronous motor inductance calibration device embodiments provided below can refer to the limitations of the permanent magnet synchronous motor inductance calibration method described above, which will not be repeated here.

[0175] In one exemplary embodiment, as shown in Figure 5 A permanent magnet synchronous motor inductance calibration device is provided, comprising: a first measurement module 501, a second measurement module 502, and an inductance calculation module 503, wherein:

[0176] The first measurement module 501 is configured to measure target calibration data of the motor to be tested at a target current test point within a first calibration period for each calibration condition; the target calibration data includes direct-axis voltage, quadrature-axis voltage, direct-axis current, quadrature-axis current, and motor torque;

[0177] The second measurement module 502 is configured to measure zero-current cross-axis voltage of the motor to be measured at a zero-current test point in a second calibration period continuous with the first calibration period.

[0178] The inductance calculation module 503 is configured to calculate inductance calibration data of the motor to be measured under the calibration operating condition based on an inductance parameter model, the target calibration data, and the zero-current cross-axis voltage.

[0179] The above permanent magnet synchronous motor inductance calibration device sets a continuous first calibration period and a second calibration period under each calibration operating condition, collects direct-axis voltage, quadrature-axis current and motor torque at the target current test point in the first calibration period, effectively avoids inductance calibration errors caused by resistance drift due to stator temperature changes by using an inductance calibration method independent of stator phase resistance as an input parameter, and measures zero-current cross-axis voltage at the zero-current test point in the second calibration period, which can effectively suppress the interference of rotor temperature change on inductance calibration. Based on this, efficient, wide temperature and high-precision inductance parameter calibration is achieved without the need for accurate temperature control.

[0180] In one embodiment, there is a corresponding target current test point for each calibration operating condition; the target current test point is located within the preset current limit circle of the motor to be measured; the first measurement module 501 is further configured to:

[0181] In the first calibration period, the motor to be measured is controlled based on the target current test point;

[0182] In the case where the operating state of the motor to be measured reaches a preset stable condition, the target calibration data of the motor to be measured at the target current test point is measured.

[0183] In one embodiment, the second measurement module 502 is configured to:

[0184] In the second calibration period, the motor to be measured is controlled based on the zero-current test point;

[0185] In the case where the operating state of the motor to be measured reaches a preset stable condition, the zero-current cross-axis voltage of the motor to be measured at the zero-current test point is measured.

[0186] In one embodiment, the permanent magnet synchronous motor inductance calibration device further comprises a model construction module, which is configured to:

[0187] Obtain a motor torque model, a flux model in a rotating coordinate system, and a voltage model in a rotating coordinate system;

[0188] Based on the direct-axis and quadrature-axis currents, the voltage model is subjected to variable reorganization processing to construct a differential voltage model;

[0189] The differential voltage model and the motor torque model are jointly solved to obtain an analytical solution of the direct-axis flux linkage and the quadrature-axis flux linkage;

[0190] The flux linkage model and the analytical solution of the direct-axis flux linkage and the quadrature-axis flux linkage are jointly solved to obtain an inductance parameter model; the inductance parameter model comprises a direct-axis inductance parameter model and a quadrature-axis inductance parameter model.

[0191] In an embodiment, the model construction module is further configured to:

[0192] The voltage model is equivalently processed based on the direct-axis current and the quadrature-axis current to obtain a direct-axis equivalent voltage model and a quadrature-axis equivalent voltage model;

[0193] The direct-axis equivalent voltage model and the quadrature-axis equivalent voltage model are differentially calculated to obtain the differential voltage model.

[0194] In an embodiment, the direct-axis current and the quadrature-axis current comprise a direct-axis current and a quadrature-axis current; the voltage model comprises a quadrature-axis voltage model and a direct-axis voltage model; the model construction module is further configured to:

[0195] The quadrature-axis voltage model is equivalently processed based on the direct-axis current to obtain a quadrature-axis equivalent voltage model;

[0196] The direct-axis voltage model is equivalently processed based on the quadrature-axis current to obtain a direct-axis equivalent voltage model.

[0197] In an embodiment, the inductance calculation module 503 is further configured to:

[0198] The target permanent magnet flux linkage of the motor to be tested under the calibration condition is calculated based on the voltage model under the rotating coordinate system and the zero-current quadrature-axis voltage;

[0199] The inductance calibration data of the motor to be tested under the calibration condition are calculated based on the inductance parameter model, the target calibration data and the target permanent magnet flux linkage.

[0200] In an embodiment, the voltage model comprises a quadrature-axis voltage model and a direct-axis voltage model; the inductance calculation module 503 is further configured to:

[0201] The zero-current quadrature-axis voltage is substituted into the quadrature-axis voltage model to obtain the direct-axis flux linkage of the motor to be tested under the calibration condition;

[0202] An analytical solution of the direct-axis flux linkage model under the rotating coordinate system is obtained;

[0203] The direct-axis flux linkage is substituted into the direct-axis flux linkage model to obtain the target permanent magnet flux linkage of the motor to be tested under the calibration condition.

[0204] In an embodiment, the inductance calculation module 503 is further configured to:

[0205] Obtaining an operation state parameter corresponding to the motor to be tested;

[0206] Solving the inductance parameter model based on the operation state parameter, the direct-axis voltage, the quadrature-axis voltage, the motor torque and the target permanent magnet flux linkage to obtain inductance calibration data of the motor to be tested under the calibration condition;

[0207] The inductance calibration data includes direct-axis inductance data and quadrature-axis inductance data.

[0208] The above modules in the permanent magnet synchronous motor inductance calibration device can be realized by software, hardware and combinations thereof. The above modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory in the computer device in software form, so as to call and execute the operations of the above modules by the processor.

[0209] In an exemplary embodiment, a computer device, which can be a server, can have an internal structure diagram as shown in Figure 6 The computer device includes a processor, a memory, an input / output interface (I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The database of the computer device is used to store permanent magnet synchronous motor inductance calibration related data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through network connection. The computer program is executed by the processor to implement a permanent magnet synchronous motor inductance calibration method.

[0210] Those skilled in the art can understand that Figure 6 The structure shown in the figure is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. The specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0211] In one embodiment, a computer device is also provided, including a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps in the above method embodiments.

[0212] In an embodiment, a computer readable storage medium is provided, having stored thereon a computer program which, when executed by a processor, implements the steps of any of the method embodiments described above.

[0213] In an embodiment, a computer program product is provided, comprising a computer program which, when executed by a processor, implements the steps of any of the method embodiments described above.

[0214] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0215] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. The non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. The volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., without being limited thereto.

[0216] The technical features of the above embodiments can be combined arbitrarily. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0217] The above-described embodiments are merely illustrative of several embodiments of the present application, and the description is relatively specific and detailed, but should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A method for calibrating the inductance of a permanent magnet synchronous motor, characterized in that, The method includes: For each calibration condition, during the first calibration period, the target calibration data of the motor under test is measured at the target current test point; the target current test point is a non-zero current test point; the target calibration data includes the right-angle axis voltage, right-angle axis current, and motor torque. During a second calibration period that is consecutive to the first calibration period, the zero-current quadrature-axis voltage of the motor under test is measured at the zero-current test point. Based on the inductance parameter model, the target calibration data, and the zero-current quadrature-axis voltage, the inductance calibration data of the motor under test under the calibration conditions are calculated. The method for constructing the inductor parameter model includes: Obtain the motor torque model, the flux linkage model in the rotating coordinate system, and the voltage model in the rotating coordinate system; Based on the right-angle current, the voltage model is reorganized to construct a differential voltage model; the differential voltage model is used to eliminate the stator phase resistance term. The differential voltage model and the motor torque model are solved together to obtain the analytical solution of the orthogonal axis flux linkage; The flux linkage model and the analytical solution of the orthogonal axis flux linkage are jointly solved to obtain the inductance parameter model; the inductance parameter model includes the orthogonal axis inductance parameter model and the quadrature axis inductance parameter model.

2. The method according to claim 1, characterized in that, Each calibration condition has a corresponding target current test point; the target current test point is located within the preset current limit circle corresponding to the motor under test; The measurement of target calibration data of the motor under test at the target current test point during the first calibration period includes: During the first calibration period, current control is performed on the motor under test based on the target current test point; When the operating state of the motor under test reaches the preset stable condition, the target calibration data of the motor under test is measured at the target current test point.

3. The method according to claim 1, characterized in that, The step of measuring the zero-current quadrature-axis voltage of the motor under test at the zero-current test point during a second calibration period that is continuous with the first calibration period includes: During the second calibration period, current control is performed on the motor under test based on the zero-current test point; When the motor under test reaches a preset stable operating condition, the zero-current quadrature-axis voltage of the motor under test is measured at the zero-current test point.

4. The method according to claim 1, characterized in that, The step of reorganizing the voltage model based on the orthogonal axis current to construct a differential voltage model includes: Based on the right-angle and quadrature-axis currents, the voltage model is equivalently processed to obtain the right-angle equivalent voltage model and the quadrature-axis equivalent voltage model; Differential calculations are performed on the direct-axis equivalent voltage model and the quadrature-axis equivalent voltage model to obtain a differential voltage model.

5. The method according to claim 4, characterized in that, The direct-axis and quadrature-axis currents include direct-axis currents and quadrature-axis currents; the voltage model includes a quadrature-axis voltage model and a direct-axis voltage model; the equivalent processing of the voltage model based on the direct-axis and quadrature-axis currents to obtain a direct-axis equivalent voltage model and a quadrature-axis equivalent voltage model includes: Based on the direct-axis current, the quadrature-axis voltage model is equivalently processed to obtain the quadrature-axis equivalent voltage model; Based on the quadrature-axis current, the direct-axis voltage model is equivalently processed to obtain the direct-axis equivalent voltage model.

6. The method according to claim 1, characterized in that, The calculation of the inductance calibration data of the motor under test under the calibration conditions, based on the inductance parameter model, the target calibration data, and the zero-current quadrature-axis voltage, includes: Based on the voltage model in the rotating coordinate system and the zero-current quadrature-axis voltage, the target permanent magnet flux of the motor under test is calculated under the calibration conditions. Based on the inductance parameter model, the target calibration data, and the target permanent magnet flux linkage, the inductance calibration data of the motor under test under the calibration conditions are calculated.

7. The method according to claim 6, characterized in that, The voltage model includes a quadrature-axis voltage model and a direct-axis voltage model; the voltage model based on the rotating coordinate system and the zero-current quadrature-axis voltage are used to calculate the target permanent magnet flux linkage of the motor under test under the calibration conditions, including: Substituting the zero-current quadrature-axis voltage into the quadrature-axis voltage model, the direct-axis flux linkage of the motor under test under the calibration conditions is obtained. Obtain the direct-axis flux linkage model in a rotating coordinate system; Substituting the direct-axis flux linkage into the direct-axis flux linkage model, the target permanent magnet flux linkage of the motor under test is obtained under the calibration conditions.

8. The method according to claim 6, characterized in that, The calculation of the inductance calibration data of the motor under test under the calibration conditions, based on the inductance parameter model, the target calibration data, and the target permanent magnet flux linkage, includes: Obtain the operating status parameters corresponding to the motor under test; Based on the operating state parameters, the right-angle axis voltage, the right-angle axis current, the motor torque, and the target permanent magnet flux linkage, the inductance parameter model is solved to obtain the inductance calibration data of the motor under test under the calibration conditions. The inductance calibration data includes direct-axis inductance data and quadrature-axis inductance data.

9. A permanent magnet synchronous motor inductance calibration device, characterized in that, The device includes: The first measurement module is used to measure the target calibration data of the motor under test at the target current test point within a first calibration period for each calibration condition; the target calibration data includes the right-angle axis voltage, right-angle axis current and motor torque; The second measurement module is used to measure the zero-current quadrature-axis voltage of the motor under test at the zero-current test point during a second calibration period that is continuous with the first calibration period. The inductance calculation module is used to calculate the inductance calibration data of the motor under test under the calibration conditions based on the inductance parameter model, the target calibration data, and the zero current quadrature-axis voltage. The model building module is used to obtain the motor torque model, the flux linkage model in the rotating coordinate system, and the voltage model in the rotating coordinate system; based on the right-angle axis current, the voltage model is reorganized to construct a differential voltage model; the differential voltage model is used to eliminate the stator phase resistance term; the differential voltage model and the motor torque model are jointly solved to obtain the analytical solution of the right-angle axis flux linkage; the flux linkage model and the analytical solution of the right-angle axis flux linkage are jointly solved to obtain the inductance parameter model; the inductance parameter model includes a right-angle inductance parameter model and a quadrature-axis inductance parameter model.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 8.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 8.

12. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 8.

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