Flux linkage observation value calculation method, system and device and computer readable storage medium

Abstract

The invention discloses a flux linkage observation value calculation method, system and device and a computer readable storage medium, and relates to the field of motor control, and the method specifically comprises the steps: determining the back electromotive force of a rotor based on a preset voltage equation; performing low-pass filtering processing on the rotor back electromotive force to obtain an initial rotor flux linkage observation value; and determining a target rotor flux linkage observation value based on a preset flux linkage value, a preset low-pass filtering transfer function and the initial rotor flux linkage observation value. The problems of integral initial value and direct current bias can be avoided, and the accuracy of the flux linkage observation value is improved.

Description

Technical Field

[0001] The present application relates to the field of motor control, and specifically to a method, system, device and computer-readable storage medium for calculating flux observation values. Background Art

[0002] With the widespread application of asynchronous motors in industry, accurate flux observation is crucial for high-performance control. The traditional method of calculating flux observation values ​​is mainly achieved through voltage models. The voltage model flux observation method does not rely on motor speed information and is insensitive to changes in rotor resistance, and has strong adaptability.

[0003] However, there is a pure integral link in the voltage model, which easily leads to problems with the initial value of the integral and the DC bias. In particular, at low speeds, the voltage amplitude at the motor terminal is small, which will make it difficult to accurately measure the voltage at the motor terminal. At the same time, during the operation of the motor, the change in the resistance of the stator resistance will cause a large error in the integrated term, thereby affecting the performance of the observer and resulting in poor accuracy of the flux observation value.

[0004] Therefore, how to avoid the initial value of integration and DC bias problems and improve the accuracy of flux observation values ​​is an issue that needs to be solved urgently. Summary of the invention

[0005] The present application provides a method, system, device and computer-readable storage medium for calculating flux observation values, which can avoid the problems of initial value of integration and DC bias and improve the accuracy of flux observation values.

[0006] In a first aspect, an embodiment of the present application provides a method for calculating a magnetic flux observation value, and the method for calculating a magnetic flux observation value includes:

[0007] Determine the rotor back EMF based on a preset voltage equation;

[0008] Performing low-pass filtering on the rotor back electromotive force to obtain an initial rotor flux observation value;

[0009] A target rotor flux observation value is determined based on a preset flux value, a preset low-pass filter transfer function, and an initial rotor flux observation value.

[0010] In combination with the first aspect, in one implementation, the rotor back EMF includes a first rotor back EMF under the α axis and a second rotor back EMF under the β axis, and determining the rotor back EMF based on a preset voltage equation includes:

[0011] Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the α-axis, and a preset stator voltage under the α-axis into the first voltage equation to obtain a first rotor back electromotive force;

[0012] Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the β axis, and a preset stator voltage under the β axis into the second voltage equation to obtain a second rotor back electromotive force;

[0013] Wherein, the calculation formula of the first voltage equation is:

[0014]

[0015] In the formula, e α is the first rotor back electromotive force; σ is the leakage magnetic coefficient; Lr is the preset rotor inductance; R S is the preset stator resistance; Lm is the mutual inductance; L s is the preset stator inductance; i α is the stator current under the α axis; u α is the stator voltage under the α axis;

[0016] The calculation formula of the second voltage equation is:

[0017]

[0018] In the formula, i β is the stator current under the β axis; u β is the stator voltage under the β axis; e β is the second rotor back EMF.

[0019] In combination with the first aspect, in one implementation, the rotor back EMF includes a first rotor back EMF under the α-axis and a second rotor back EMF under the β-axis, and the low-pass filtering of the rotor back EMF to obtain an initial rotor flux observation value includes:

[0020] Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the first rotor back electromotive force into the first calculation formula for low-pass filtering to obtain a first initial rotor flux observation value;

[0021] Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second rotor back electromotive force into the second calculation formula for low-pass filtering to obtain a second initial rotor flux observation value;

[0022] Wherein, the first calculation formula is:

[0023]

[0024] Where s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; e αis the first rotor back EMF; is the first initial rotor flux observation value;

[0025] The second calculation formula is:

[0026]

[0027] In the formula, e β is the second rotor back EMF; is the second initial rotor flux observation value.

[0028] In combination with the first aspect, in one implementation, the preset flux value includes a preset first flux value under the α-axis and a preset second flux value under the β-axis, the initial rotor flux observation value includes a first initial rotor flux observation value under the α-axis and a second initial rotor flux observation value under the β-axis, and determining the target rotor flux observation value based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value includes:

[0029] Substituting a preset first flux value, a preset complex frequency variable in Laplace transform, a preset cutoff angular frequency of the low-pass filter, and a first initial rotor flux observation value into a third calculation formula to obtain a first target rotor flux observation value;

[0030] Substituting the preset second flux value, the preset complex frequency variable in the Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second initial rotor flux observation value into the fourth calculation formula to obtain the second target rotor flux observation value;

[0031] Wherein, the third calculation formula is:

[0032]

[0033] In the formula, is the first initial rotor flux observation value; is the preset first flux value; s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; ψ ′ α is the first target rotor flux observation value;

[0034] The fourth calculation formula is:

[0035]

[0036] In the formula, is the second initial rotor flux observation value; is the preset second flux linkage value; ψ ′ βis the second target rotor flux observation value.

[0037] In combination with the first aspect, in one implementation, the target rotor flux observation value includes a first target rotor flux observation value under the α-axis and a second target rotor flux observation value under the β-axis, and after the step of determining the target rotor flux observation value based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value, the step further includes:

[0038] Performing an inverse tangent calculation on the first target rotor flux observation value and the second target rotor flux observation value to obtain a rotor flux observation angle;

[0039] Motor control is performed based on the rotor flux observation angle.

[0040] In a second aspect, an embodiment of the present application provides a magnetic flux observation value calculation system, the magnetic flux observation value calculation system comprising:

[0041] A first processing module, which is used to determine the rotor back electromotive force based on a preset voltage equation;

[0042] A second processing module, which is used to perform low-pass filtering on the rotor back electromotive force to obtain an initial rotor flux observation value;

[0043] The third processing module is used to determine a target rotor flux observation value based on a preset flux value, a preset low-pass filter transfer function, and an initial rotor flux observation value.

[0044] In conjunction with the second aspect, in one implementation, the first processing module is specifically configured to:

[0045] Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the α-axis, and a preset stator voltage under the α-axis into a preset first voltage equation to obtain a first rotor back electromotive force;

[0046] Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the β axis, and a preset stator voltage under the β axis into a preset second voltage equation to obtain a second rotor back electromotive force;

[0047] Wherein, the calculation formula of the first voltage equation is:

[0048]

[0049] In the formula, e α is the first rotor back electromotive force; σ is the leakage magnetic coefficient; Lr is the preset rotor inductance; R S is the preset stator resistance; Lm is the mutual inductance; L sis the preset stator inductance; i α is the stator current under the α axis; u α is the stator voltage under the α axis;

[0050] The calculation formula of the second voltage equation is:

[0051]

[0052] In the formula, i β is the stator current under the β axis; u β is the stator voltage under the β axis; e β is the second rotor back EMF.

[0053] In conjunction with the second aspect, in one implementation, the second processing module is specifically configured to:

[0054] Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the first rotor back electromotive force into the first calculation formula for low-pass filtering to obtain a first initial rotor flux observation value;

[0055] Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second rotor back electromotive force into the second calculation formula for low-pass filtering to obtain a second initial rotor flux observation value;

[0056] Wherein, the first calculation formula is:

[0057]

[0058] Where s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; e α is the first rotor back EMF; is the first initial rotor flux observation value;

[0059] The second calculation formula is:

[0060]

[0061] In the formula, e β is the second rotor back EMF; is the second initial rotor flux observation value.

[0062] In a third aspect, an embodiment of the present application provides a magnetic flux observation value calculation device, which includes a processor, a memory, and a magnetic flux observation value calculation program stored in the memory and executable by the processor, wherein when the magnetic flux observation value calculation program is executed by the processor, the steps of the magnetic flux observation value calculation method described in any of the above items are implemented.

[0063] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a magnetic flux observation value calculation program is stored. When the magnetic flux observation value calculation program is executed by a processor, the steps of the magnetic flux observation value calculation method as described in any of the above items are implemented.

[0064] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0065] The rotor back EMF is determined based on a preset voltage equation, and the rotor back EMF is low-pass filtered to obtain an initial rotor flux observation value, thereby avoiding error accumulation and initial value dependence caused by direct integration, making the flux observation smoother and more stable; the target rotor flux observation value is determined based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value, thereby further optimizing the accuracy and response speed of the flux, solving the error caused by the change of stator resistance, and improving the observation accuracy of the system under different operating conditions, thereby obtaining a more accurate flux observation value. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a flow chart of an embodiment of a method for calculating magnetic flux observation values ​​of the present application;

[0067] Figure 2 This is a schematic diagram of the flow of calculating the rotor flux observation angle in the embodiment of the method for calculating the flux observation value of the present application;

[0068] Figure 3 This is a schematic diagram of the functional modules of an embodiment of the magnetic flux observation value calculation system of the present application;

[0069] Figure 4 This is a schematic diagram of the hardware structure of a magnetic flux observation value calculation device involved in the embodiment of the present application. DETAILED DESCRIPTION

[0070] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0071] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0072] In a first aspect, an embodiment of the present application provides a method for calculating a magnetic flux observation value.

[0073] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of an embodiment of the method for calculating the magnetic flux observation value of the present application. Figure 1 As shown in Figure 2, the calculation method of magnetic flux observation value includes:

[0074] Step S10: Determine the rotor back electromotive force based on a preset voltage equation.

[0075] Exemplarily, in the embodiment of the present application, the preset voltage equation refers to the voltage equation of the asynchronous motor, which includes parameters such as stator voltage, stator current, stator resistance and rotor back EMF. During the operation of the motor, there is an interaction between the stator voltage and the rotor back EMF; the generation of the rotor back EMF is based on Faraday's law of electromagnetic induction. Specifically, when the motor rotor rotates, the magnetic field generated by the permanent magnet or armature current on the rotor cuts the magnetic lines of force in the stator winding, thereby inducing an electromotive force in the stator winding, which is the rotor back EMF.

[0076] Specifically, when the motor rotor rotates, the rotor cuts the magnetic lines of force in the magnetic field generated by the stator. According to Faraday's law of electromagnetic induction, a back electromotive force is induced in the rotor, which can be calculated by the change of the rotor magnetic flux and the change of the speed. It should be understood that by appropriately transforming the voltage equation, the expression of the rotor back electromotive force can be obtained, so that the specific value can be calculated based on the known parameters such as the stator voltage and the stator current and using the derivation formula of the rotor back electromotive force.

[0077] Step S20: low-pass filter the rotor back EMF to obtain an initial rotor flux observation value.

[0078] For example, in an embodiment of the present application, since the rotor back EMF usually contains high-frequency noise components, directly using the back EMF signal to calculate the flux observation value may lead to inaccurate results; therefore, the back EMF signal can be low-pass filtered to replace the integration link to effectively remove the higher frequency noise components and only retain the low-frequency signal related to the rotor flux change.

[0079] Specifically, the signal after low-pass filtering represents a relatively stable and real rotor back-EMF signal, and the initial rotor flux observation value can be obtained by making corresponding estimates of the signal; at this time, low-pass filtering not only reduces the influence of noise on the accuracy of flux estimation, but also improves the stability and reliability of the estimation, making the initial rotor flux observation value more accurate and consistent with the actual motor operating state.

[0080] Step S30: Determine a target rotor flux observation value based on a preset flux value, a preset low-pass filter transfer function, and an initial rotor flux observation value.

[0081] Exemplarily, in an embodiment of the present application, the specific value of the preset flux value (i.e., the given flux value) can be determined according to the operating target or control requirement of the asynchronous motor, which represents the rotor flux state that the motor should achieve, and is not limited here; the preset low-pass filter transfer function describes how the filter smoothes the output according to changes in the input signal.

[0082] Specifically, the initial rotor flux observation value is compensated under the joint action of the preset flux value and the low-pass filter to obtain a target rotor flux observation value with high accuracy; that is, through the determination of the preset low-pass filter transfer function and the preset flux value, the system can dynamically feedback and adjust the initial flux observation value to gradually reach and maintain the desired target rotor flux state. This process plays an important role in optimizing performance and achieving precise control in motor control.

[0083] The present application determines the rotor back EMF based on a preset voltage equation, and obtains the initial rotor flux observation value by low-pass filtering the rotor back EMF, thereby avoiding the error accumulation and initial value dependence caused by direct integration, making the flux observation smoother and more stable; the target rotor flux observation value is determined based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value, further optimizing the accuracy and response speed of the flux, solving the error caused by the change of stator resistance, and improving the observation accuracy of the system under different operating conditions, thereby obtaining more accurate flux observation values.

[0084] Further, in one embodiment, the rotor back EMF includes a first rotor back EMF under the α axis and a second rotor back EMF under the β axis, and the rotor back EMF is determined based on a preset voltage equation, including:

[0085] Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the α-axis, and a preset stator voltage under the α-axis into the first voltage equation to obtain a first rotor back electromotive force;

[0086] Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the β axis, and a preset stator voltage under the β axis into the second voltage equation to obtain a second rotor back electromotive force;

[0087] Wherein, the calculation formula of the first voltage equation is:

[0088]

[0089] In the formula, e α is the first rotor back electromotive force; σ is the leakage magnetic coefficient; Lr is the preset rotor inductance; R S is the preset stator resistance; Lm is the mutual inductance; L s is the preset stator inductance; i α is the stator current under the α axis; u α is the stator voltage under the α axis;

[0090] The calculation formula of the second voltage equation is:

[0091]

[0092] In the formula, i β is the stator current under the β axis; u β is the stator voltage under the β axis; e β is the second rotor back EMF.

[0093] Exemplarily, in an embodiment of the present application, the rotor back EMF includes a first rotor back EMF under the α-axis and a second rotor back EMF under the β-axis. The preset first voltage equation is used to calculate the first rotor back EMF, and the preset second voltage equation is used to calculate the second rotor back EMF. The specific values ​​of the preset rotor inductance, the preset leakage magnetic coefficient, the preset mutual inductance, the preset stator resistance, the preset stator inductance, the preset stator current under the α-axis, the preset stator voltage under the α-axis, the stator current under the β-axis, and the stator voltage under the β-axis can be determined according to actual needs and are not limited here.

[0094] Specifically, the leakage magnetic coefficient σ, the preset rotor inductance Lr, the preset stator resistance R S , mutual inductance Lm, preset stator inductance L s 、The stator current i under the α axis α , stator voltage u under α axis α Substituting into the first voltage equation, we get the first rotor back EMF e α , the first voltage equation is as follows:

[0095]

[0096] The leakage magnetic coefficient σ, the preset rotor inductance Lr, the preset stator resistance RS , mutual inductance Lm, preset stator inductance L s , stator current i under β axis β , stator voltage u under β axis β Substituting into the second voltage equation, we get the second rotor back EMF e β , the second voltage equation is as follows:

[0097]

[0098] Further, in one embodiment, the rotor back EMF includes a first rotor back EMF under the α axis and a second rotor back EMF under the β axis, and the low-pass filtering of the rotor back EMF to obtain the initial rotor flux observation value includes:

[0099] Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the first rotor back electromotive force into the first calculation formula for low-pass filtering to obtain a first initial rotor flux observation value;

[0100] Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second rotor back electromotive force into the second calculation formula for low-pass filtering to obtain a second initial rotor flux observation value;

[0101] Wherein, the first calculation formula is:

[0102]

[0103] Where s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; e α is the first rotor back EMF; is the first initial rotor flux observation value;

[0104] The second calculation formula is:

[0105]

[0106] In the formula, e β is the second rotor back EMF; is the second initial rotor flux observation value.

[0107] Exemplarily, in an embodiment of the present application, the rotor back EMF includes a first rotor back EMF under the α-axis and a second rotor back EMF under the β-axis. The specific values ​​of the complex frequency variable in the preset Laplace transform and the cutoff angular frequency of the preset low-pass filter can be determined according to actual needs and are not limited here. The low-pass filter transfer function is composed of the complex frequency variable in the Laplace transform and the cutoff angular frequency of the low-pass filter.

[0108] Specifically, the complex frequency variable s in the Laplace transform and the cutoff angular frequency ω of the low-pass filter are c , the first rotor back EMF e α Substitute the following calculation formula for low-pass filtering to obtain the first initial rotor flux observation value The calculation formula is:

[0109]

[0110] The complex frequency variable s in the Laplace transform and the cutoff angular frequency ω of the low-pass filter c , the second rotor back EMF e β Substitute the following calculation formula for low-pass filtering to obtain the second initial rotor flux observation value: The calculation formula is:

[0111]

[0112] Further, in one embodiment, the preset flux value includes a preset first flux value under the α-axis and a preset second flux value under the β-axis, the initial rotor flux observation value includes a first initial rotor flux observation value under the α-axis and a second initial rotor flux observation value under the β-axis, and the target rotor flux observation value is determined based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value, including:

[0113] Substituting a preset first flux value, a preset complex frequency variable in Laplace transform, a preset cutoff angular frequency of the low-pass filter, and a first initial rotor flux observation value into a third calculation formula to obtain a first target rotor flux observation value;

[0114] Substituting the preset second flux value, the preset complex frequency variable in the Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second initial rotor flux observation value into the fourth calculation formula to obtain the second target rotor flux observation value;

[0115] Wherein, the third calculation formula is:

[0116]

[0117] In the formula, is the first initial rotor flux observation value; is the preset first flux value; s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; ψ ′ α is the first target rotor flux observation value;

[0118] The fourth calculation formula is:

[0119]

[0120] In the formula, is the second initial rotor flux observation value; is the preset second flux linkage value; ψ ′ β is the second target rotor flux observation value.

[0121] Exemplarily, in an embodiment of the present application, the preset flux value includes a preset first flux value under the α-axis and a preset second flux value under the β-axis, wherein the specific values ​​of the preset first flux value and the preset second flux value can be determined according to actual needs and are not limited here; the initial rotor flux observation value includes a first initial rotor flux observation value under the α-axis and a second initial rotor flux observation value under the β-axis; the preset low-pass filter transfer function is composed of a complex frequency variable in the Laplace transform and a cutoff angular frequency of the low-pass filter.

[0122] Specifically, the first initial rotor flux observation value Preset the first flux value Complex frequency variable s in Laplace transform, cutoff angular frequency ω of low-pass filter c Substitute the following calculation formula to obtain the first target rotor flux observation value ψ ′ α , the calculation formula is:

[0123]

[0124] The second initial rotor flux observation value Preset the second flux value Complex frequency variable s in Laplace transform, cutoff angular frequency ω of low-pass filter c Substitute the following calculation formula to obtain the second target rotor flux observation value ψ ′ β , the calculation formula is:

[0125]

[0126] Further, in one embodiment, referring to Figure 2As shown, the target rotor flux observation value includes a first target rotor flux observation value under the α axis and a second target rotor flux observation value under the β axis. After the step of determining the target rotor flux observation value based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value, the step further includes:

[0127] Step P10: performing an inverse tangent calculation on the first target rotor flux observation value and the second target rotor flux observation value to obtain a rotor flux observation angle;

[0128] Step P20: Control the motor based on the rotor flux observation angle.

[0129] Exemplarily, in the embodiment of the present application, the target rotor flux observation value includes a first target rotor flux observation value under the α-axis and a second target rotor flux observation value under the β-axis. Specifically, the first target rotor flux observation value and the second target rotor flux observation value are substituted into the following calculation formula for inverse tangent calculation to obtain the rotor flux observation angle. The calculation formula is:

[0130]

[0131] In the formula, ψ ′ α is the first target rotor flux observation value; ψ ′ β is the second target rotor flux observation value; is the rotor flux observation angle.

[0132] It should be noted that after determining the rotor flux observation angle, the motor can be adjusted and controlled in real time according to the rotor flux observation angle to optimize the motor's current and voltage waveforms and ensure that the motor operates under the required working conditions. It is understandable that by accurately controlling the rotor flux observation angle, the motor control system can achieve efficient power output, precise speed control, and stable operating performance, while reducing energy loss and thermal effects, and improving overall drive efficiency and system stability.

[0133] In a second aspect, an embodiment of the present application also provides a magnetic flux observation value calculation system.

[0134] In one embodiment, referring to Figure 3 , Figure 3 This is a functional module diagram of an embodiment of the magnetic flux observation value calculation system of the present application. Figure 3 As shown, the magnetic flux observation value calculation system includes:

[0135] A first processing module, which is used to determine the rotor back electromotive force based on a preset voltage equation;

[0136] A second processing module, which is used to perform low-pass filtering on the rotor back electromotive force to obtain an initial rotor flux observation value;

[0137] The third processing module is used to determine a target rotor flux observation value based on a preset flux value, a preset low-pass filter transfer function, and an initial rotor flux observation value.

[0138] Furthermore, in one embodiment, the first processing module is specifically configured to:

[0139] Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the α-axis, and a preset stator voltage under the α-axis into a preset first voltage equation to obtain a first rotor back electromotive force;

[0140] Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the β axis, and a preset stator voltage under the β axis into a preset second voltage equation to obtain a second rotor back electromotive force;

[0141] Wherein, the calculation formula of the first voltage equation is:

[0142]

[0143] In the formula, e α is the first rotor back electromotive force; σ is the leakage magnetic coefficient; Lr is the preset rotor inductance; R S is the preset stator resistance; Lm is the mutual inductance; L s is the preset stator inductance; i α is the stator current under the α axis; u α is the stator voltage under the α axis;

[0144] The calculation formula of the second voltage equation is:

[0145]

[0146] In the formula, i β is the stator current under the β axis; u β is the stator voltage under the β axis; e β is the second rotor back EMF.

[0147] Furthermore, in one embodiment, the second processing module is specifically configured to:

[0148] Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the first rotor back electromotive force into the first calculation formula for low-pass filtering to obtain a first initial rotor flux observation value;

[0149] Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second rotor back electromotive force into the second calculation formula for low-pass filtering to obtain a second initial rotor flux observation value;

[0150] Wherein, the first calculation formula is:

[0151]

[0152] Where s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; e α is the first rotor back EMF; is the first initial rotor flux observation value;

[0153] The second calculation formula is:

[0154]

[0155] In the formula, e β is the second rotor back EMF; is the second initial rotor flux observation value.

[0156] Furthermore, in one embodiment, the third processing module is specifically used for:

[0157] Substituting a preset first flux value, a preset complex frequency variable in Laplace transform, a preset cutoff angular frequency of the low-pass filter, and a first initial rotor flux observation value into a third calculation formula to obtain a first target rotor flux observation value;

[0158] Substituting the preset second flux value, the preset complex frequency variable in the Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second initial rotor flux observation value into the fourth calculation formula to obtain the second target rotor flux observation value;

[0159] Wherein, the third calculation formula is:

[0160]

[0161] In the formula, is the first initial rotor flux observation value; is the preset first flux value; s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; ψ ′ α is the first target rotor flux observation value;

[0162] The fourth calculation formula is:

[0163]

[0164] In the formula, is the second initial rotor flux observation value; is the preset second flux linkage value; ψ ′ β is the second target rotor flux observation value.

[0165] Furthermore, in one embodiment, the first processing module is further configured to:

[0166] Performing an inverse tangent calculation on the first target rotor flux observation value and the second target rotor flux observation value to obtain a rotor flux observation angle;

[0167] Motor control is performed based on the rotor flux observation angle.

[0168] The present application determines the rotor back EMF based on a preset voltage equation, and obtains the initial rotor flux observation value by low-pass filtering the rotor back EMF, thereby avoiding the error accumulation and initial value dependence caused by direct integration, making the flux observation smoother and more stable; the target rotor flux observation value is determined based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value, further optimizing the accuracy and response speed of the flux, solving the error caused by the change of stator resistance, and improving the observation accuracy of the system under different operating conditions, thereby obtaining more accurate flux observation values.

[0169] Among them, the functional implementation of each module in the above-mentioned magnetic flux observation value calculation system corresponds to the various steps in the above-mentioned magnetic flux observation value calculation method embodiment, and its functions and implementation processes are no longer repeated here one by one.

[0170] In a third aspect, an embodiment of the present application provides a magnetic flux observation value calculation device, which may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0171] Reference Figure 4 , Figure 4 The hardware structure diagram of the magnetic flux observation value calculation device involved in the embodiment of the present application is shown in FIG. In the embodiment of the present application, the magnetic flux observation value calculation device may include a processor, a memory, a communication interface, and a communication bus.

[0172] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0173] The communication interface includes input / output (I / O) interface, physical interface and logical interface, etc., which are used to realize the interconnection of devices inside the flux observation value calculation device, and the interface used to realize the interconnection between the flux observation value calculation device and other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, a fiber optic interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0174] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0175] The processor may be a general-purpose processor, and the general-purpose processor may call the magnetic flux observation value calculation program stored in the memory and execute the magnetic flux observation value calculation method provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the magnetic flux observation value calculation program is called may refer to the various embodiments of the magnetic flux observation value calculation method of the present application, and will not be repeated here.

[0176] Those skilled in the art will understand that Figure 4 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0177] In a fourth aspect, an embodiment of the present application also provides a readable storage medium.

[0178] The readable storage medium of the present application stores a magnetic flux observation value calculation program, wherein when the magnetic flux observation value calculation program is executed by a processor, the steps of the magnetic flux observation value calculation method as described above are implemented.

[0179] Among them, the method implemented when the magnetic flux observation value calculation program is executed can refer to the various embodiments of the magnetic flux observation value calculation method of the present application, and will not be repeated here.

[0180] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0181] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0182] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0183] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0184] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0185] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0186] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for calculating magnetic flux observation value, characterized in that: The magnetic flux observation value calculation method includes: Determine the rotor back EMF based on a preset voltage equation; Performing low-pass filtering on the rotor back electromotive force to obtain an initial rotor flux observation value; A target rotor flux observation value is determined based on a preset flux value, a preset low-pass filter transfer function, and an initial rotor flux observation value.

2. The method for calculating magnetic flux observation value according to claim 1, characterized in that: The rotor back EMF includes a first rotor back EMF under the α axis and a second rotor back EMF under the β axis, and the rotor back EMF is determined based on a preset voltage equation, including: Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the α-axis, and a preset stator voltage under the α-axis into the first voltage equation to obtain a first rotor back electromotive force; Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the β axis, and a preset stator voltage under the β axis into the second voltage equation to obtain a second rotor back electromotive force; Wherein, the calculation formula of the first voltage equation is: In the formula, e a is the first rotor back electromotive force; σ is the leakage magnetic coefficient; Lr is the preset rotor inductance; R S is the preset stator resistance; Lm is the mutual inductance; L s is the preset stator inductance; i α is the stator current under the α axis; u α is the stator voltage under the α axis; The calculation formula of the second voltage equation is: In the formula, i β is the stator current under the β axis; u β is the stator voltage under the β axis; e β is the second rotor back EMF.

3. The method for calculating magnetic flux observation value according to claim 1, characterized in that: The rotor back EMF includes a first rotor back EMF under the α axis and a second rotor back EMF under the β axis, and the low-pass filtering of the rotor back EMF to obtain an initial rotor flux observation value includes: Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the first rotor back electromotive force into the first calculation formula for low-pass filtering to obtain a first initial rotor flux observation value; Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second rotor back electromotive force into the second calculation formula for low-pass filtering to obtain a second initial rotor flux observation value; Wherein, the first calculation formula is: Where s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; e α is the first rotor back EMF; is the first initial rotor flux observation value; The second calculation formula is: In the formula, e β is the second rotor back EMF; is the second initial rotor flux observation value.

4. The method for calculating magnetic flux observation value according to claim 1, characterized in that: The preset flux value includes a preset first flux value under the α axis and a preset second flux value under the β axis, the initial rotor flux observation value includes a first initial rotor flux observation value under the α axis and a second initial rotor flux observation value under the β axis, and the target rotor flux observation value is determined based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value, including: Substituting a preset first flux value, a preset complex frequency variable in Laplace transform, a preset cutoff angular frequency of the low-pass filter, and a first initial rotor flux observation value into a third calculation formula to obtain a first target rotor flux observation value; Substituting the preset second flux value, the preset complex frequency variable in the Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second initial rotor flux observation value into the fourth calculation formula to obtain the second target rotor flux observation value; Wherein, the third calculation formula is: In the formula, is the first initial rotor flux observation value; is the preset first flux value; s is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; ψ ′ α is the first target rotor flux observation value; The fourth calculation formula is: In the formula, is the second initial rotor flux observation value; is the preset second flux value; ψ ′ β is the second target rotor flux observation value.

5. The method for calculating magnetic flux observation value according to claim 1, characterized in that: The target rotor flux observation value includes a first target rotor flux observation value under the α axis and a second target rotor flux observation value under the β axis. After the step of determining the target rotor flux observation value based on the preset flux value, the preset low-pass filter transfer function, and the initial rotor flux observation value, the method further includes: Performing an inverse tangent calculation on the first target rotor flux observation value and the second target rotor flux observation value to obtain a rotor flux observation angle; Motor control is performed based on the rotor flux observation angle.

6. A magnetic flux observation value calculation system, characterized in that: The magnetic flux observation value calculation system comprises: A first processing module, which is used to determine the rotor back electromotive force based on a preset voltage equation; A second processing module, which is used to perform low-pass filtering on the rotor back electromotive force to obtain an initial rotor flux observation value; The third processing module is used to determine a target rotor flux observation value based on a preset flux value, a preset low-pass filter transfer function, and an initial rotor flux observation value.

7. The magnetic flux observation value calculation system according to claim 6, characterized in that: The first processing module is specifically used for: Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the α-axis, and a preset stator voltage under the α-axis into a preset first voltage equation to obtain a first rotor back electromotive force; Substituting a preset rotor inductance, a preset magnetic leakage coefficient, a preset mutual inductance, a preset stator resistance, a preset stator inductance, a preset stator current under the β axis, and a preset stator voltage under the β axis into a preset second voltage equation to obtain a second rotor back electromotive force; Wherein, the calculation formula of the first voltage equation is: In the formula, e α is the first rotor back electromotive force; σ is the leakage magnetic coefficient; Lr is the preset rotor inductance; R S is the preset stator resistance; Lm is the mutual inductance; L s is the preset stator inductance; i α is the stator current under the α axis; u α is the stator voltage under the α axis; The calculation formula of the second voltage equation is: In the formula, i β is the stator current under the β axis; u β is the stator voltage under the β axis; e β is the second rotor back EMF.

8. The magnetic flux observation value calculation system according to claim 6, characterized in that: The second processing module is specifically used for: Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the first rotor back electromotive force into the first calculation formula for low-pass filtering to obtain a first initial rotor flux observation value; Substituting the complex frequency variable in the preset Laplace transform, the preset cutoff angular frequency of the low-pass filter, and the second rotor back electromotive force into the second calculation formula for low-pass filtering to obtain a second initial rotor flux observation value; Wherein, the first calculation formula is: Where, is the complex frequency variable in Laplace transform, ω c is the cut-off frequency of the low-pass filter, is the low-pass filter transfer function; e α is the first rotor back EMF; is the first initial rotor flux observation value; The second calculation formula is: In the formula, e β is the second rotor back EMF; is the second initial rotor flux observation value.

9. A magnetic flux observation value calculation device, characterized in that: The magnetic flux observation value calculation device includes a processor, a memory, and a magnetic flux observation value calculation program stored in the memory and executable by the processor, wherein when the magnetic flux observation value calculation program is executed by the processor, the steps of the magnetic flux observation value calculation method according to any one of claims 1 to 5 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a magnetic flux observation value calculation program, wherein when the magnetic flux observation value calculation program is executed by a processor, the steps of the magnetic flux observation value calculation method according to any one of claims 1 to 5 are implemented.

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