Method, device, electronic device and storage medium for identifying parameters of AC motor

Abstract

The present application discloses a method, device, electronic device and storage medium for identifying parameters of an AC motor, and relates to the technical field of motor control. The method includes the following steps: determining a reference result based on the obtained stator three-phase current and three-phase flux; obtaining the rotor flux in the αβ two-phase stationary coordinate system based on the joint solution of the stator three-phase current and the current rotor time constant, and then obtaining an adjustable result through the rotor flux; obtaining a new rotor time constant based on the reference result and the adjustable result. The present application does not require an integrator and a stator resistor for calculation, which not only avoids the problems of integrator temperature drift and integration error accumulation caused by the pure integration link, but also solves the drawback of inaccurate rotor time constant calculation caused by the error of the stator resistance, and can also accurately identify the rotor time constant of the motor at low speed and light load, thereby improving the steady-state performance of the motor.

Description

Technical Field

[0001] The present application relates to the technical field of motor control, and in particular to a method, device, electronic device and storage medium for identifying parameters of an AC motor. Background Art

[0002] Among the high-performance control algorithms for AC motors, vector control or field-oriented control is the most widely used. As for vector control, the key lies in field orientation, and one of the important factors for the accuracy of field orientation lies in the accuracy of parameters, so accurate identification of motor parameters is very necessary and critical.

[0003] The parameters mainly involve rotor time constant, stator resistance, etc. The inaccuracy of these parameters will lead to increased errors in magnetic field orientation; among them, the rotor time constant Tr is the biggest factor affecting the accuracy of magnetic field orientation of induction motors. If the motor is in operation for a long time, the rotor resistance will increase with the increase in temperature, and the rotor time constant will also change with the working state of the motor. Assuming that the rotor time constant deviates too much from the actual value, the magnetic field orientation will be seriously inaccurate, the decoupling of the motor flux and torque will fail, the steady-state performance and dynamic performance of the motor will be reduced, and even violent oscillation of the motor will be caused. It can be seen that the key to accurately realize vector control lies in the accurate identification of motor parameters, especially the accurate identification of the rotor time constant.

[0004] In the related art, methods for identifying rotor time constants include model reference adaptive algorithms, etc. In the traditional model reference adaptive algorithms, a rotor flux observer based on a voltage model that is independent of the rotor time constant is often selected as a reference model, and a rotor flux observer based on a current model that is independent of the rotor time constant is often selected as an adjustable model. The difference between the output of the adjustable model and the reference model is passed through an adaptive link to obtain an estimated value of the rotor time constant, and the rotor time constant in the above-mentioned adjustable model is dynamically adjusted according to the estimated value.

[0005] However, the reference model in this related technology uses a voltage model observer to estimate the magnetic flux, introducing a pure integration link. The temperature drift problem of the integrator, the initial value of the integral and the error accumulation will also cause large errors in the estimation of the magnetic flux, making the magnetic field orientation inaccurate.

[0006] At the same time, when the motor runs at low speed, the voltage drop of the stator resistance is obvious. If the parameter value of the stator resistance is inaccurate, the deviation of the voltage drop will also lead to more serious integration result errors in related technologies, which will lead to greater estimation errors of the rotor time constant at low speed. Summary of the invention

[0007] The embodiment of the present application provides a method for identifying the rotor time constant of an AC motor to solve the technical problem of insufficient accuracy in identifying the rotor time constant in motor parameters in the related art.

[0008] In a first aspect, a method for identifying parameters of an AC motor is provided, comprising the following steps:

[0009] Determine a reference result according to the obtained stator three-phase current and three-phase flux;

[0010] The magnetic flux of the rotor in the αβ two-phase stationary coordinate system is obtained by jointly solving the three-phase current of the stator and the current rotor time constant, and then an adjustable result is obtained through the magnetic flux of the rotor;

[0011] A new rotor time constant is obtained according to the reference result and the adjustable result.

[0012] In some embodiments, the specific steps of jointly solving the three-phase current of the stator and the current rotor time constant to obtain the magnetic flux of the rotor in the αβ two-phase stationary coordinate system include:

[0013] Parker transforms the three-phase current of the stator to obtain the current α-axis and β-axis components of the stator in the αβ two-phase stationary coordinate system;

[0014] The α and β axis components of the stator current, the acquired rotor angular velocity and the current rotor time constant are substituted into the rotor flux current model in the αβ two-phase stationary coordinate system to obtain the α and β axis components of the rotor flux.

[0015] In some embodiments, the mathematical formula of the rotor flux current model is:

[0016]

[0017]

[0018] In the formula, ψ rα , ψ rβ are the α and β axis components of the rotor flux;

[0019] i sα ,i sβ are the α and β axis components of the stator current;

[0020] T r is the rotor time constant;

[0021] p is a differential operator;

[0022] ω r is the rotor angular velocity;

[0023] L mis the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system.

[0024] In some embodiments, the specific steps of obtaining an adjustable result through the magnetic flux of the rotor include:

[0025] Substitute the stator current α, β axis components and the rotor flux α, β axis components, as well as the acquired rotor angular velocity and the current rotor time constant into the set adjustable model to obtain an adjustable result; wherein the mathematical formula of the adjustable model is:

[0026]

[0027] In the formula, is the stator transient inductance;

[0028] L s is the stator self-inductance in the αβ two-phase stationary coordinate system, including the stator leakage inductance;

[0029] L m is the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system;

[0030] L r is the rotor self-inductance in the αβ two-phase stationary coordinate system, including the rotor leakage inductance;

[0031] T r is the rotor time constant;

[0032] p is a differential operator;

[0033] is the stator current amplitude;

[0034] ω r is the rotor angular velocity;

[0035] ψ rα ,ψ rβ are the α and β axis components of the rotor flux;

[0036] i sα ,i sβ are the α and β axis components of the stator current.

[0037] In some embodiments, the specific step of determining a reference result according to the obtained stator three-phase current and three-phase flux includes:

[0038] Obtain the stator flux and stator current in the abc three-phase symmetrical coordinate system;

[0039] Substitute the stator flux and stator current into the set reference model to obtain a reference result; wherein the data formula of the reference model is:

[0040] F1=ψ ai a +ψ b i b +ψ c i c ,

[0041] In the formula, i a ,i b ,i c They represent the three-phase currents a, b and c of the stator respectively;

[0042] ψ a ,ψ b ,ψ c They represent the a, b, and c three-phase flux of the stator respectively.

[0043] In some embodiments, the specific steps of obtaining a new rotor time constant according to the reference result and the adjustable result include:

[0044] A new rotor time constant is determined based on the difference between the reference result and the adjustable result.

[0045] In some embodiments, the specific steps of obtaining a new rotor time constant according to the reference result and the adjustable result include:

[0046] Substitute the reference result and the adjustable result into the Popov stability theory model to obtain a new rotor time constant; wherein the mathematical formula of the Popov stability theory model is:

[0047]

[0048] In the formula, k p ,k i is the proportional coefficient, F1 is the reference result, F2 is the adjustable result, T r (0) is the rotor time constant at the initial moment.

[0049] In a second aspect, a device for identifying parameters of an AC motor is also provided, comprising:

[0050] A first module is configured to determine a reference result according to the acquired stator three-phase current and three-phase flux;

[0051] The second module is configured to jointly solve the rotor flux in the αβ two-phase stationary coordinate system according to the current observation value of the rotor time constant and the three-phase current of the stator, and then obtain an adjustable result through the rotor flux;

[0052] The third module is configured to estimate a new observation value of the rotor time constant according to the adjustable result obtained by the second module and the reference result determined by the first module, and send the new observation value to the second module as the observation value of the rotor time constant.

[0053] In a third aspect, an electronic device is also provided, comprising a memory and a processor, wherein the memory stores a computer program running on the processor, and when the processor executes the computer program, the steps of the method for identifying parameters of an AC motor as described above are implemented.

[0054] In a fourth aspect, a storage medium is also provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method for identifying parameters of an AC motor as described above are implemented.

[0055] The beneficial effects brought about by the technical solution provided in the present application include: no need for integrator and stator resistance for calculation, which not only avoids the problems of integrator temperature drift and integration error accumulation caused by the pure integration link, but also solves the disadvantage of inaccurate calculation of rotor time constant caused by the error of stator resistance, and can also accurately identify the rotor time constant of the motor at low speed and light load, thereby improving the steady-state performance of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0057] Figure 1 A flowchart of a method for identifying the rotor time constant of an AC motor provided in an embodiment of the present application;

[0058] Figure 2 To jointly solve and obtain the topological diagram of the α and β axis components of the rotor flux;

[0059] Figure 3 This is a topological diagram of the new rotor time constant obtained from the reference model and the adjustable model.

[0060] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, 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 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 making creative work are within the scope of protection of this application.

[0062] The flowcharts shown in the accompanying drawings are only examples and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may also be decomposed, combined or partially merged, so the actual execution order may change according to actual conditions.

[0063] The embodiment of the present application provides a method for identifying the parameters of an AC motor without the need for an integrator and stator resistance for calculation. This avoids the problems of integrator temperature drift and integration error accumulation caused by a pure integration link, solves the problem of inaccurate rotor time constant calculation caused by the error of the stator resistance, and can accurately identify the rotor time constant of the motor at low speed and light load, thereby improving the steady-state performance of the motor.

[0064] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0065] like Figure 1 As shown, the embodiment of the present application provides a method for identifying parameters of an AC motor, comprising the following steps:

[0066] S001: Determine a reference result according to the obtained stator three-phase current and three-phase flux;

[0067] S002: jointly solving the three-phase current of the stator and the current rotor time constant to obtain the magnetic flux of the rotor in the αβ two-phase stationary coordinate system, and then obtaining an adjustable result through the magnetic flux of the rotor;

[0068] S003: Obtain a new rotor time constant according to the reference result and the adjustable result.

[0069] In the conventional reference adaptive model, the three-phase voltage and three-phase current of the stator in the abc three-phase symmetrical coordinate system are first obtained, and then the voltage of each phase is integrated. This will result in the disadvantages of integrator temperature drift and integration error accumulation caused by the pure integration link.

[0070] Among them, the above reference adaptive model is:

[0071] F=i a ∫u a +i b ∫u b +i c ∫u c ,

[0072] In the formula, u a ,u b ,u c Respectively represent the three-phase voltages of the stator a, b, and c, i a ,i b,i c They represent the a, b, and c three-phase currents of the stator respectively.

[0073] According to the voltage equation of AC motor Combined with the above reference adaptive model, a deformed reference adaptive model containing stator current, stator flux and stator resistance is obtained. The expression of the deformed reference adaptive model is:

[0074] F=ψ a i a +ψ b i b +ψ c i c +Δ(R s ),

[0075] In the formula, ψ a , ψ b , ψ c They represent the three-phase flux of the stator a, b, and c respectively;

[0076] Δ(R s ) contains the stator resistance and stator current. If the stator current is expressed in the form of instantaneous value, this term can be expressed as:

[0077] Δ(R s )=R s I 2 [cos(ωt)∫cos(ωt)dt+cos(ωt-120°)∫cos(ωt-120°)dt+cos(ωt-240°)∫cos(ωt-240°)dt]=0,

[0078] If the motor is in steady state, then Δ(R s ) is zero, which shows that the stator resistance will not affect the results of the improved reference adaptive model in steady state.

[0079] Furthermore, in steady state, the improved reference adaptive model in the abc three-phase symmetrical coordinate system can be expressed as:

[0080] F=F(u a ,u b ,u c ,i a ,i b ,i c )=ψ a i a +ψ b i b +ψ c i c

[0081] In the formula, i a,i b ,i c Respectively represent the a, b, c three-phase currents of the stator;

[0082] ψ a , ψ b , ψ c They represent the a, b, and c three-phase flux of the stator respectively.

[0083] The improved reference adaptive model is defined as the reference model, and the mathematical formula of the reference model is:

[0084] F1=ψ a i a +ψ b i b +ψ c i c ,

[0085] In the formula, i a ,i b ,i c Respectively represent the a, b, c three-phase currents of the stator;

[0086] ψ a , ψ b , ψ c They represent the a, b, and c three-phase flux of the stator respectively.

[0087] Based on this, in a preferred solution of the embodiment of the present application, the specific steps of step S001 include:

[0088] Obtain the stator flux and stator current in the abc three-phase symmetrical coordinate system;

[0089] Substitute the stator flux and stator current into the set reference model to obtain a reference result; wherein the data formula of the reference model is:

[0090] F1=ψ a i a +ψ b i b +ψ c i c ,

[0091] In the formula, i a ,i b ,i c Respectively represent the a, b, c three-phase currents of the stator;

[0092] ψ a , ψ b , ψ c They represent the a, b, and c three-phase flux of the stator respectively.

[0093] In an embodiment of the present application, an improvement and optimization is performed on the basis of the traditional model reference adaptation to obtain a reference model, which only contains stator voltage and stator current. In steady state, it can be equivalent to an expression containing only stator flux and stator current, solving the problems of temperature drift and integral error accumulation of the integrator of the traditional voltage-type flux observer.

[0094] like Figure 2 As shown, preferably, the specific steps of jointly solving the three-phase current of the stator and the current rotor time constant to obtain the magnetic flux of the rotor in the αβ two-phase stationary coordinate system include:

[0095] Parker transforms the three-phase current of the stator to obtain the current α-axis and β-axis components of the stator in the αβ two-phase stationary coordinate system;

[0096] The α and β axis components of the stator current, the acquired rotor angular velocity and the current rotor time constant are substituted into the rotor flux current model in the αβ two-phase stationary coordinate system to obtain the α and β axis components of the rotor flux.

[0097] Specifically, the mathematical formula of the rotor flux current model is:

[0098]

[0099]

[0100] In the formula, ψ rα ,ψ rβ are the α and β axis components of the rotor flux;

[0101] i sα ,i sβ are the α and β axis components of the stator current;

[0102] T r is the rotor time constant;

[0103] p is a differential operator;

[0104] ω r is the rotor angular velocity;

[0105] L m is the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system.

[0106] Specifically, the steps of obtaining an adjustable result through the magnetic flux of the rotor include:

[0107] Substitute the stator current α, β axis components and the rotor flux α, β axis components, as well as the acquired rotor angular velocity and the current rotor time constant into the set adjustable model to obtain an adjustable result; wherein the mathematical formula of the adjustable model is:

[0108]

[0109] In the formula, is the stator transient inductance;

[0110] L s is the stator self-inductance in the αβ two-phase stationary coordinate system, including the stator leakage inductance;

[0111] L m is the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system;

[0112] L r is the rotor self-inductance in the αβ two-phase stationary coordinate system, including the rotor leakage inductance;

[0113] T r is the rotor time constant;

[0114] p is a differential operator;

[0115] is the stator current amplitude;

[0116] ω r is the rotor angular velocity;

[0117] ψ rα ,ψ rβ are the α and β axis components of the rotor flux;

[0118] i sα ,i sβ are the α and β axis components of the stator current.

[0119] According to the above reference model, its physical meaning is the sum of the products of the three-phase flux of the stator and the corresponding phase current. When the reference model is expressed in the αβ two-phase stationary coordinate system, according to the flux equation of the induction motor in the αβ two-phase stationary coordinate system, the new expression of the reference model in the αβ two-phase stationary coordinate system is simplified:

[0120]

[0121] Where, L s is the stator self-inductance in the αβ two-phase stationary coordinate system, including the stator leakage inductance;

[0122] L m is the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system;

[0123] L r is the rotor self-inductance in the αβ two-phase stationary coordinate system, including the rotor leakage inductance;

[0124] is the stator current amplitude;

[0125] ψ rα ,ψ rβ are the α and β axis components of the rotor flux;

[0126] i sα ,i sβ are the α and β axis components of the stator current.

[0127] At the same time, the expression of the rotor flux current model can be determined by the voltage equation and flux equation of the induction motor in the αβ two-phase stationary coordinate system:

[0128]

[0129]

[0130] In the formula, ψ rα ,ψ rβ are the α and β axis components of the rotor flux;

[0131] i sα ,i sβ are the α and β axis components of the stator current;

[0132] T r is the rotor time constant;

[0133] p is a differential operator;

[0134] ω r is the rotor angular velocity;

[0135] L m is the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system.

[0136] Then, the expression of the rotor flux current model is combined with the new expression of the reference model in the αβ two-phase stationary coordinate system. After simplification, the expression of the adjustable model in the αβ two-phase stationary coordinate system can be determined as follows:

[0137]

[0138] In the formula, is the stator transient inductance;

[0139] L s is the stator self-inductance in the αβ two-phase stationary coordinate system, including the stator leakage inductance;

[0140] L m is the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system;

[0141] L r is the rotor self-inductance in the αβ two-phase stationary coordinate system, including the rotor leakage inductance;

[0142] Tr is the rotor time constant;

[0143] p is a differential operator;

[0144] is the stator current amplitude;

[0145] ω r is the rotor angular velocity;

[0146] ψ rα , ψ rβ are the α and β axis components of the rotor flux;

[0147] i sα ,i sβ are the α and β axis components of the stator current.

[0148] In the embodiment of the present application, the rotor flux is observed by a current type flux observer, and the specific principle diagram is as follows: Figure 2 As shown, since the current-type flux observer containing the rotor time constant is used as a part of the adjustable model, the magnetic field orientation error caused by the inaccurate rotor time constant can be reflected and compensated.

[0149] Preferably, the specific steps of obtaining a new rotor time constant according to the reference result and the adjustable result include:

[0150] A new rotor time constant is determined based on the difference between the reference result and the adjustable result.

[0151] Specifically, the specific steps of obtaining a new rotor time constant according to the reference result and the adjustable result include:

[0152] Substitute the reference result and the adjustable result into the Popov stability theory model to obtain a new rotor time constant; wherein the mathematical formula of the Popov stability theory model is:

[0153]

[0154] In the formula, k p ,k i is the proportional coefficient, F1 is the reference result, F2 is the adjustable result, T r (0) is the rotor time constant at the initial moment.

[0155] Among them, the rotor time constant at the initial moment is a known value.

[0156] In an embodiment of the present application, an adjustable model is established in an αβ two-phase stationary coordinate system, and the adjustable model is also combined with a current model flux observer with a rotor time constant. The rotor time constant is estimated by Popov hyperstable theory to achieve online adjustment and identification of the rotor time constant, and accurately identify the rotor time constant. The steps are simple and the implementation is convenient, so that the rotor time constant identification vector control system in the AC motor parameters constructed based on the embodiment of the present application runs stably, has strong practicality, and is easy to promote and use.

[0157] It should be emphasized that, firstly, the parameters selected for the reference model only include the stator three-phase flux and current, but not the stator resistance; secondly, the adjustable model contains the rotor flux, which can also overcome the magnetic field orientation error caused by inaccurate stator resistance; finally, the output of the reference model is subtracted from the output of the adjustable model, and then the closed-loop feedback adaptive mitigation is performed, so that the observed parameter rotor time constant in the adjustable model can be adjusted, which solves the inaccurate influence of the stator resistance error on the rotor time constant, avoids the influence of the pure integral link in the voltage-type flux observer used in the traditional method, and improves the robustness to the stator resistance; at the same time, at low speed and light load, the rotor time constant in the motor parameters can also be accurately identified to improve the steady-state performance of the system.

[0158] The present application also provides a device for identifying parameters of an AC motor, including:

[0159] A first module is configured to determine a reference result according to the acquired stator three-phase current and three-phase flux;

[0160] The second module is configured to jointly solve the rotor flux in the αβ two-phase stationary coordinate system according to the current observation value of the rotor time constant and the three-phase current of the stator, and then obtain an adjustable result through the rotor flux;

[0161] The third module is configured to estimate a new observation value of the rotor time constant according to the adjustable result obtained by the second module and the reference result determined by the first module, and send the new observation value to the second module as the observation value of the rotor time constant.

[0162] It should be noted that those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described device and each module can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0163] An embodiment of the present application also provides an electronic device, including a memory and a processor. The memory stores a computer program running on the processor, and when the processor executes the computer program, the steps of the method for identifying AC motor parameters as described above are implemented.

[0164] An embodiment of the present application further provides a storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for identifying parameters of an AC motor as described above are implemented.

[0165] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0166] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0167] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for identifying parameters of an AC motor, characterized in that: The following steps are involved: Determine a reference result according to the obtained stator three-phase current and three-phase flux; The magnetic flux of the rotor in the αβ two-phase stationary coordinate system is obtained by jointly solving the three-phase current of the stator and the current rotor time constant, and then an adjustable result is obtained through the magnetic flux of the rotor; Obtaining a new rotor time constant according to the reference result and the adjustable result; The specific steps of determining a reference result according to the obtained stator three-phase current and three-phase flux include: Obtain the stator flux and stator current in the abc three-phase symmetrical coordinate system; Substitute the stator flux and stator current into the set reference model to obtain a reference result; wherein the data formula of the reference model is: F1=ψ a I a +ψ b I b +ψ c I c , In the formula, i a ,i b ,i c They represent the three-phase currents a, b and c of the stator respectively; ψ a ,ψ b ,ψ c They represent the a, b, and c three-phase flux of the stator respectively; The specific steps of obtaining an adjustable result through the magnetic flux of the rotor include: Substitute the stator current α, β axis components and the rotor flux α, β axis components, as well as the acquired rotor angular velocity and the current rotor time constant into the set adjustable model to obtain an adjustable result; wherein the mathematical formula of the adjustable model is: In the formula, is the stator transient inductance; L s is the stator self-inductance in the αβ two-phase stationary coordinate system, including the stator leakage inductance; L m is the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system; L r is the rotor self-inductance in the αβ two-phase stationary coordinate system, including the rotor leakage inductance; T r is the rotor time constant; p is a differential operator; is the stator current amplitude; ω r is the rotor angular velocity; ψ rα ,ψ rβ are the α and β axis components of the rotor flux; i sα ,i sβ are the α and β axis components of the stator current; The specific steps of obtaining a new rotor time constant according to the reference result and the adjustable result include: A new rotor time constant is determined based on the difference between the reference result and the adjustable result.

2. The method for identifying parameters of an AC motor according to claim 1, characterized in that: The specific steps of jointly solving the three-phase current of the stator and the current rotor time constant to obtain the magnetic flux of the rotor in the αβ two-phase stationary coordinate system include: Parker transforms the three-phase current of the stator to obtain the current α-axis and β-axis components of the stator in the αβ two-phase stationary coordinate system; The α and β axis components of the stator current, the acquired rotor angular velocity and the current rotor time constant are substituted into the rotor flux current model in the αβ two-phase stationary coordinate system to obtain the α and β axis components of the rotor flux.

3. The method for identifying AC motor parameters according to claim 2, characterized in that: The mathematical formula of the rotor flux current model is: In the formula, ψ rα ,ψ rβ are the α and β axis components of the rotor flux; i sα ,i sβ are the α and β axis components of the stator current; T r is the rotor time constant; p is a differential operator; ω r is the rotor angular velocity; L m is the mutual inductance between the stator and the rotor in the αβ two-phase stationary coordinate system.

4. The method for identifying parameters of an AC motor according to claim 1, characterized in that: The specific steps of obtaining a new rotor time constant according to the reference result and the adjustable result include: Substitute the reference result and the adjustable result into the Popov stability theory model to obtain a new rotor time constant; wherein the mathematical formula of the Popov stability theory model is: In the formula, k p ,k i is the proportional coefficient, F1 is the reference result, F2 is the adjustable result, T r (0) is the rotor time constant at the initial moment.

5. A device using the method for identifying parameters of an AC motor as claimed in claim 1, characterized in that: include: A first module is configured to determine a reference result according to the acquired stator three-phase current and three-phase flux; The second module is configured to jointly solve the rotor flux in the αβ two-phase stationary coordinate system according to the current observation value of the rotor time constant and the three-phase current of the stator, and then obtain an adjustable result through the rotor flux; The third module is configured to estimate a new observation value of the rotor time constant according to the adjustable result obtained by the second module and the reference result determined by the first module, and send the new observation value to the second module as the observation value of the rotor time constant.

6. An electronic device comprising a memory and a processor, wherein the memory stores a computer program running on the processor, characterized in that: When the processor executes the computer program, the steps of the method for identifying parameters of an AC motor as described in any one of claims 1 to 4 are implemented.

7. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for identifying parameters of an AC motor as claimed in any one of claims 1 to 4 are implemented.

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