CN111917350A - A multi-parameter identification method for a permanent magnet-assisted synchronous reluctance motor with adjustable flux linkage - Google Patents

Abstract

The invention discloses a multi-parameter identification method of a permanent magnet assisted synchronous reluctance motor with adjustable flux linkage. With the cooperation of a torque flux linkage control algorithm, the parameter identification method proposed by the present invention is mainly divided into four steps: Step A It is a static inductance data table and iron loss current data table established based on off-line finite element electromagnetic field analysis; step B is based on the high-frequency component of high-frequency equivalent resistance and dynamic inductance identification; step C is based on the fundamental frequency component of the stator resistance and permanent Magnetic flux linkage identification; Step D is the separation of different coercive force flux linkages and rotor temperature identification. The method of the invention can not only realize the on-line identification of multiple physical parameters such as static/dynamic inductance, stator resistance, permanent magnetic flux linkage, rotor temperature, etc. Dynamic separation of magnetic flux linkages.

Description

A multi-parameter identification method for a permanent magnet-assisted synchronous reluctance motor with adjustable flux linkage

technical field

The invention relates to a multi-parameter identification method of a permanent magnet auxiliary synchronous reluctance motor with adjustable flux linkage, and belongs to the technical field of motor parameter identification.

Background technique

The permanent magnet-assisted synchronous reluctance motor with adjustable flux linkage adopts the hybrid excitation mode of permanent magnet and direct-axis current, and adopts permanent magnet torque to assist the reluctance torque. Coercive permanent magnets, so this type of motor has good comprehensive motor performance in terms of torque density, power factor, efficiency, magnetic adjustment capability, and fault tolerance. The high-performance control and improved torque performance of the permanent magnet-assisted synchronous reluctance motor with adjustable flux linkage are inseparable from the online identification of the motor model parameters.

The parameter identification of the existing permanent magnet synchronous motor is mainly divided into the following categories: 1) The motor parameter identification method based on the fundamental frequency component of the motor. Generally speaking, the number of state equations of the motor is often less than the number of parameters to be identified. It is necessary to adopt some parameter rated value setting, disturbance injection and other methods to solve the under-rank problem of the motor parameter identification. 2) The motor parameter identification method based on the high frequency voltage and current signal model of the motor. By injecting high-frequency voltage signal or flux linkage excitation signal into the motor, the high-frequency voltage or current response signal is extracted, and then parameters such as motor inductance are observed in real time according to the mathematical model of the motor's high-frequency signal. 3) The motor parameter identification method based on the temperature physical characteristics of parameters such as resistance and flux linkage. The stator resistance and permanent magnet flux linkage parameters are identified online by the back EMF method and the high frequency signal injection method combined with the physical characteristics of temperature.

Different from the traditional permanent magnet synchronous motor, the permanent magnet assisted synchronous reluctance motor with adjustable flux linkage has the inherent characteristics of rich magnetic field space harmonics, tight AC/DC current coupling, strong rotor saliency, and nonlinear time-varying parameters. Therefore, it brings difficulties to the online identification of motor parameters. Under the premise of stable control of torque, how to realize multi-parameter identification of permanent magnet-assisted synchronous reluctance motors with adjustable flux linkage has become an urgent problem to be solved in high-performance motor control and wide industrial applications.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is: to provide a multi-parameter identification method for a permanent magnet assisted synchronous reluctance motor with adjustable flux linkage, which combines the parameter identification method with offline finite element electromagnetic field analysis, data storage, and data fitting. The influence of multiple factors such as space magnetic field harmonics, magnetic saturation, AC/DC axis coupling, and temperature changes on the motor model is considered, and the torque is free from pulsation during parameter identification.

The present invention adopts the following technical solutions for solving the above-mentioned technical problems:

A multi-parameter identification method for a permanent magnet assisted synchronous reluctance motor with adjustable flux linkage, comprising the following steps:

Step 1, establish a static inductance database and a loss database based on off-line finite element electromagnetic field analysis;

Step 2, when the adjustable flux linkage permanent magnet auxiliary synchronous reluctance motor is in flux linkage torque control, set the frequency of the high-frequency pulsed flux linkage signal, and inject the high-frequency pulsed flux linkage signal into the straight axis and the quadrature axis respectively, And based on this, the dynamic inductance and high-frequency equivalent resistance are identified;

Step 3, stop the injection of the high-frequency pulsed flux linkage signal, and identify the stator resistance and the permanent magnet flux linkage based on the fundamental frequency component, the static inductance database and the loss database;

In step 4, the rotor temperature is identified by combining the high-frequency equivalent resistance identified in step 2 and the stator resistance identified in step 3, and the permanent magnet flux linkages with different coercive forces are separated based on the rotor temperature.

As a preferred version of the present invention, the specific process of the step 2 is as follows:

Step 2.1, when the adjustable flux linkage permanent magnet assisted synchronous reluctance motor is in flux linkage torque control, set the frequency ω _h1 of the high-frequency pulsed flux linkage signal, and inject the high-frequency pulsed flux linkage from the direct axis and the quadrature axis respectively. signal, obtain the pulsed flux linkage amplitude |λ _sh | and the direct-axis current i _d1 in the steady state of the straight-axis injection, and obtain the pulsed flux linkage amplitude |λ _sh | current i _q1 ;

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Step 2.2, using the discrete Fourier analysis method to analyze the direct-axis current i _d1 and the quadrature-axis current i _q1 to obtain the high-frequency component amplitude I _dh1 of the direct-axis current and the high-frequency component amplitude I _qh1 of the quadrature-axis current. The amplitude of the frequency pulsed flux linkage signal |λ _sh |, the direct-axis dynamic inductance is calculated

and quadrature dynamic inductance

Step 2.3, when the adjustable flux linkage permanent magnet assisted synchronous reluctance motor is in flux linkage torque control, set the frequency ω _h2 of the high-frequency pulsed flux linkage signal, and inject the high-frequency pulsed flux linkage signal from the direct axis to obtain a steady state In the case of direct axis voltage u _d2 , direct axis current i _d2 ;

Step 2.4, using the discrete Fourier analysis method to analyze the direct-axis voltage u _d2 and the direct-axis current i _d2 to obtain the direct-axis voltage high-frequency component amplitude U _dh2 and the direct-axis current high-frequency component amplitude I _dh2 , combined with the current high The frequency ω _h2 of the frequency pulsed flux linkage signal calculates the high frequency equivalent resistance R _eqh .

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计算公式如下：As a preferred solution of the present invention, the direct-axis dynamic inductor

and quadrature dynamic inductance

Calculated as follows:

The formula for calculating the high frequency equivalent resistance R _eqh is as follows:

Among them, N is the number of sampling points, ω _s is the sampling angular frequency of the system, j is the imaginary unit, i _d1 (k), i _q1 (k) are the direct-axis current and quadrature-axis current of the kth sampling, respectively, i _d2 (k ) and u _d2 (k) are the direct-axis current and direct-axis voltage of the kth sampling, respectively.

As a preferred solution of the present invention, the specific process of the step 3 is as follows:

Step 3.1, stop the injection of the high-frequency pulsed flux linkage signal, and set the initial value of the permanent magnetic flux linkage λ _pm (i=0);

Step 3.2, obtaining the stator direct-axis voltage _ud , the quadrature-axis voltage u _q , the stator direct-axis current _id , the quadrature-axis current i _q , and the rotational speed ω _r in a steady state;

Step 3.3, according to the static inductance database established in step 1, use the current permanent magnet flux linkage λ _pm (i) and the stator direct axis current _id and the quadrature axis current i _q to obtain the direct and quadrature axis static inductances L _d , L _q ;

Step 3.4, according to the loss database established in step 1, utilize the current permanent magnet flux linkage λ _pm (i) and the stator direct axis current _id and quadrature axis current i _q to obtain the direct and quadrature axis loss currents _idF and i _qF ;

Step 3.5, according to the direct and quadrature axis loss currents i _dF , i _qF , the stator direct axis voltage _ud , the quadrature axis voltage u _q , the stator direct axis current _id , the quadrature axis current i _q , and the rotational speed ω _r , calculate the stator resistance R _s and permanent magnetic flux linkage λ _pm ;

Step 3.6, compare the current permanent magnetic flux linkage λ _pm (i) with the permanent magnetic flux linkage λ _pm calculated in step 3.5, when the error |λ _pm (i)-λ _pm | is less than or equal to the set allowable range λ _Δ , go to step 3.9; when the error |λ _pm (i)-λ _pm | is greater than the set allowable range λ _Δ , go to step 3.7;

Step 3.7, increase the iteration count i=i+1;

Step 3.8, set the permanent magnetic flux linkage to the calculated value λ _pm (i)=λ _pm , and return to step 3.2;

Step 3.9, end the iterative process, the calculated values of stator resistance and permanent magnet flux linkage.

As a preferred solution of the present invention, the calculation formula of the stator resistance R _s is as follows:

The formula for calculating the permanent magnetic flux linkage λ _pm is as follows:

As a preferred solution of the present invention, the specific process of the step 4 is as follows:

Step 4.1, obtain the temperature physical properties of the permanent magnets with different coercivity, and establish a data table λ=LUT_T(T) of its permanent magnet flux linkage and temperature;

Step 4.2: Measure the stator winding temperature T ₀ before operation, and combine the high-frequency equivalent resistance R _eqh (0) at the initial moment provided by Step 2 and the stator resistance R _s (0) at the initial moment provided by Step 3 to obtain the rotor equivalent resistance the initial value R _reqh (0) and the initial value of the rotor temperature T _r0 ;

R _reqh (0)=R _eqh (0)-R _s (0)

T _r0 =T ₀

Step 4.3, combining the high-frequency equivalent resistance R _eqh (t) at time t provided in step 2 and the stator resistance R _s (t) at time t provided in step 3, calculate the high-frequency signal injection lower rotor equivalent resistance R _reqh (t) and rotor temperature _Tr ;

R _reqh (t)=R _eqh (t)-R _s (t)

Among them, α is the temperature coefficient of the rotor equivalent resistance;

Step 4.4, according to the temperature characteristics of the high-coercivity permanent magnet and in combination with the rotor temperature provided in step 4.3, calculate its permanent magnetic flux linkage λ _HCF =LUT_T(T _r );

Step 4.5, separate the permanent magnetic flux linkage λ _LCF of low coercivity according to the permanent magnetic flux linkage λ _HCF of high coercivity:

λ _LCF = λ _pm - λ _HCF

Among them, λ _pm is the permanent magnet flux linkage.

Compared with the prior art, the present invention adopts the above technical scheme, and has the following technical effects:

1. The present invention combines the motor parameter identification method with the motor offline finite element electromagnetic field analysis, data storage, and data fitting, and the motor control model comprehensively considers space magnetic field harmonics, magnetic saturation, AC/DC coupling, and temperature changes. Therefore, the motor mathematical model used for multi-parameter identification of the permanent magnet-assisted synchronous reluctance motor with adjustable flux linkage is more accurate.

2. The present invention adopts the injection of high-frequency flux linkage signals in different frequency bands, and under the premise of stably controlling the motor torque, it can simultaneously realize the online identification of the motor dynamic inductance and the motor high-frequency resistance, and provide a basis for the temperature observation of the motor.

3. According to the different temperature characteristics of different permanent magnets and combined with the temperature identification of the motor rotor, the present invention can realize the separation of the flux linkages of the permanent magnets with different coercive forces, which is a low-coercive method for the adjustable flux linkage permanent magnet auxiliary synchronous reluctance motor system. Coercive permanent magnets are charged/demagnetized online to provide the magnetization state of the permanent magnet flux linkage.

4. The present invention makes full use of the finite element offline electromagnetic field analysis, high-frequency signal injection and state observation, fundamental frequency state equation observation, and multi-information fusion of permanent magnet temperature physical characteristics to provide mutual support information, effectively and accurately realize the flux linkage. Online identification of multiple physical parameters such as static/dynamic inductance, stator resistance, permanent magnet flux linkage, rotor temperature, etc. of the permanent magnet-assisted synchronous reluctance motor.

Description of drawings

Figure 1 is a multi-parameter identification control block diagram of a flux linkage adjustable permanent magnet assisted synchronous reluctance motor based on flux linkage torque control.

FIG. 2 is a flow chart of a multi-parameter identification method of a permanent magnet-assisted synchronous reluctance motor with adjustable flux linkage according to the present invention.

Figure 3 is a flowchart of high-frequency equivalent resistance and inductance identification based on high-frequency components.

Figure 4 is a flow chart of stator resistance and permanent magnet flux linkage identification based on fundamental frequency components.

FIG. 5 is a flowchart of the separation of flux linkages with different coercive forces and the identification of rotor temperature.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, but not to be construed as a limitation of the present invention.

As shown in Figure 1 and Figure 2, with the cooperation of the torque flux linkage control algorithm, on the one hand, the torque flux linkage control algorithm implements the injection of high-frequency flux linkage signals, and on the other hand, the torque flux linkage control algorithm provides the magnetic flux High frequency flux linkage λ _sh , rotational speed ω _r , stator temperature T ₀ , AC and direct axis voltage _udq and current i _dq in steady state of the adjustable permanent magnet assisted synchronous reluctance motor.

Based on this, the parameter identification method proposed by the present invention is mainly divided into four steps:

Step A is the static inductance data table and the iron loss current data table established based on the off-line finite element electromagnetic field analysis;

Step B is based on the high-frequency equivalent resistance and dynamic inductance identification of high-frequency components, and the specific steps are shown in Figure 3:

Step B.1: When the adjustable flux linkage permanent magnet-assisted synchronous reluctance motor is in flux linkage torque control, set the frequency ω _h1 of the high-frequency pulsed flux linkage signal, and its frequency satisfies the following relationship:

where ω _s is the sampling angular frequency of the system, which may be set as

The pulsed flux linkage signal is injected into the direct axis, and its expression is as follows:

Then, the steady-state data during direct-axis injection are obtained, including the pulsed flux linkage amplitude |λ _sh | and the direct-axis current i _d1 .

The quadrature axis injects the pulsed flux linkage signal, and its expression is as follows:

Then, the steady-state data during quadrature-axis injection are obtained, including the amplitude of the pulsed flux |λ _sh | and the quadrature-axis current i _q1 .

Step B.2: Using Discrete Fourier Transform (DFT) to analyze the direct-axis current i _d1 and the quadrature-axis current i _q1 , the amplitude I _dh1 of the high-frequency component of the direct-axis current and the high-frequency component of the quadrature-axis current can be obtained Amplitude I _qh1 , its formula is as follows:

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Among them, N is the number of sampling points, ω _s is the sampling angular frequency of the system, and i _d1 (k) and i _q1 (k) are the direct-axis current and quadrature-axis current of the kth sampling, respectively. Combined with the amplitude |λ _sh | of the high-frequency pulsed flux linkage signal at this time, the direct-axis dynamic inductance is finally calculated.

and quadrature dynamic inductance

Step B.3: When the adjustable flux linkage permanent magnet assisted synchronous reluctance motor is in flux linkage torque control, set the frequency ω _h2 of the high frequency pulsed flux linkage signal, and its frequency satisfies the following relationship:

则此时高频脉振磁链信号表达式如下：Where ω _h1 is the high-frequency flux linkage frequency set in step B.1, it may be set as

Then the high-frequency pulsed flux linkage signal expression is as follows:

Then obtain steady-state data, including direct-axis voltage _ud2 and direct-axis current i _d2 .

Step B.4: Using DFT to analyze the direct-axis voltage u _d2 and the direct-axis current i _d2 , the direct-axis current high-frequency component amplitude I _dh2 and the direct-axis voltage high-frequency component amplitude U _dh2 can be obtained:

Among them, N is the number of sampling points, ω _s is the sampling angular frequency of the system, and i _d2 (k) and u _d2 (k) are the direct-axis current and direct-axis voltage of the kth sampling, respectively. Then, the high-frequency equivalent resistance Re _eqh is calculated in combination with the frequency ω _h2 of the high-frequency pulsed flux linkage signal at this time.

Step C is based on the stator resistance and permanent magnet flux linkage identification based on the fundamental frequency component, and the specific steps are shown in Figure 4:

Step C.1: Stop the injection of the high-frequency flux linkage signal, and set the initial value of the permanent magnet flux linkage λ _pm (i=0).

Step C.2: In order to obtain steady-state data, including stator voltage _udq (including _ud and u _q ), current _idq (including _id and i _q ), and rotational speed ω _r .

Step C.3: According to the static inductance database LUT_L(λ _pm (i), i _d , i _q ) provided in step A, use the current permanent magnet flux linkage λ _pm (i) and the stator current _{id dq} to obtain the static inductance L _d , _Lq .

Step C.4: According to the loss database _{LUT_F} (λ _pm (i), id , i _q ) provided in step A, use the current permanent magnet flux linkage λ _pm (i) and the stator current _{id q to obtain the loss current idF ,} i _qF .

Step C.5: Calculate the stator resistance R _s and the permanent magnetic flux linkage λ _pm according to the loss current i _dF , i _qF , the stator voltage _{udq and the current i dq ,} the rotational speed ω _r and so on.

Step C.6: The error comparison module compares the set permanent magnetic flux linkage λ _pm (i) with the calculated permanent magnetic flux linkage λ _pm . When the error |λ _pm (i)-λ _pm | is less than or equal to the setting allowable range λ _Δ , then go to step C.9. If the error |λ _pm (i)-λ _pm | is larger than the set allowable range λ _Δ , go to step C.7.

Step C.7: Increment the iteration count i=i+1.

Step C.8: Set the permanent magnetic flux linkage to the calculated value λ _pm (i)=λ _pm , and return to step C.2.

Step C.9: End the iterative process and save the calculated values, then the stator resistance R _s and the permanent magnet magnetic λ _pm chain can be obtained.

The formula for calculating the stator resistance is as follows:

Therefore, the calculation formula of permanent magnetic flux linkage is as follows:

Step D is the separation of flux linkages with different coercive forces and the identification of rotor temperature. The specific steps are shown in Figure 5:

Step D.1: Obtain the temperature physical properties of permanent magnets with different coercivity, and establish a data table λ=LUT_T(T) of their permanent magnet flux linkage and temperature.

Step D.2: First measure the stator winding temperature T ₀ before working, and combine the high-frequency equivalent resistance R _eqh (0) provided by step B and the stator winding resistance R _s (0) provided by step C, so as to obtain the rotor equivalent The resistance initial value R _reqh (0) and the rotor temperature initial value T _r0 .

R _reqh (0)=R _eqh (0)-R _s (0) (12)

T _r0 =T ₀ (13)

Step D.3: Combined with the high-frequency equivalent resistance R _eqh (t) provided in step B and the stator winding resistance R _s (t) provided in step C, the rotor equivalent resistance R _reqh (t) under the high-frequency signal injection can be calculated. ) to obtain the rotor temperature _Tr .

R _reqh (t) = R _eqh (t) - R _s (t) (14)

The coefficient α is the temperature coefficient of the rotor equivalent resistance.

Step D.4: Calculate its permanent magnetic flux linkage λ _HCF = _{LUT_T} (Tr ) according to the temperature characteristics of the high coercivity permanent magnet (NdFeB permanent magnet) combined with the rotor temperature provided in Step D.3.

Step D.5: According to these two sets of data, the permanent magnetic flux linkage λ _LCF of low coercivity (low coercivity permanent magnets, such as AlNiCo, Samarium Cobalt and other permanent magnets) can be separated, as shown in the following formula:

λ _LCF = λ _pm - λ _HCF (16)

Where LUT_T is the data table of the permanent magnet flux linkage of the high coercivity permanent magnet with temperature.

The above embodiments are only to illustrate the technical idea of the present invention, and cannot limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the present invention. Inside.

Claims (6)

1. A multi-parameter identification method for a flux linkage adjustable permanent magnet auxiliary synchronous reluctance motor is characterized by comprising the following steps:

step 1, establishing a static inductance database and a loss database based on offline finite element electromagnetic field analysis;

step 2, when the flux linkage adjustable permanent magnet auxiliary synchronous reluctance motor is under flux linkage torque control, setting the frequency of a high-frequency pulse vibration flux linkage signal, respectively injecting the high-frequency pulse vibration flux linkage signal into a direct axis and a quadrature axis, and identifying the dynamic inductance and the high-frequency equivalent resistance based on the high-frequency pulse vibration flux linkage signal;

step 3, stopping injecting the high-frequency pulse vibration flux linkage signal, and identifying the stator resistance and the permanent magnet flux linkage based on the fundamental frequency component, the static inductance database and the loss database;

and 4, identifying the temperature of the rotor by combining the high-frequency equivalent resistor identified in the step 2 and the stator resistor identified in the step 3, and separating the permanent magnet flux linkages with different coercive forces based on the temperature of the rotor.

2. The multi-parameter identification method of the flux linkage adjustable permanent magnet assisted synchronous reluctance motor according to claim 1, wherein the specific process of the step 2 is as follows:

step 2.1, when the flux linkage adjustable permanent magnet auxiliary synchronous reluctance motor is in flux linkage torque control, setting the frequency omega of the high-frequency pulse vibration flux linkage signal_h1Respectively injecting high-frequency pulse vibration magnetic linkage signals from a direct axis and a quadrature axis to obtain the pulse vibration magnetic linkage amplitude | lambda | under the steady-state condition during the direct axis injection_shI, direct axis current i_d1Obtaining the amplitude of the magnetic linkage of the pulsating vibration in the steady state condition when the quadrature axis is injected_shI, quadrature axis current i_q1；

Step 2.2, analyzing the direct-axis current i by using a discrete Fourier analysis method_d1And quadrature axis current i_q1To obtainAmplitude I of high-frequency component of current to direct axis_dh1Amplitude I of high-frequency component of quadrature axis current_qh1Combined with the amplitude | λ of the high frequency pulsating flux linkage signal at that time_shCalculating the dynamic inductance of the straight axis

Dynamic inductance of quadrature axis

Step 2.3, when the flux linkage adjustable permanent magnet auxiliary synchronous reluctance motor is in flux linkage torque control, setting the frequency omega of the high-frequency pulse vibration flux linkage signal_h2Obtaining the direct-axis voltage u under the steady-state condition by injecting a high-frequency pulse vibration flux linkage signal from the direct axis_d2Direct axis current i_d2；

Step 2.4, analyzing the direct-axis voltage u by using a discrete Fourier analysis method_d2And a direct axis current i_d2Obtaining the high-frequency component amplitude U of the direct-axis voltage_dh2And the amplitude I of the high-frequency component of the direct-axis current_dh2Combined with the frequency omega of the high-frequency pulse-vibration magnetic linkage signal_h2Calculating the equivalent resistance R of high frequency_eqh。

3. The method of claim 2, wherein the direct axis dynamic inductor is used for multi-parameter identification of the flux linkage adjustable PMSM

Dynamic inductance of quadrature axis

The calculation formula is as follows:

high frequency equivalent resistance R_eqhThe calculation formula is as follows:

wherein N is the number of sampling points, omega_sFor the system sampling angular frequency, j denotes the imaginary unit, i_d1(k)、i_q1(k) Respectively the direct axis current and the quadrature axis current i of the kth sampling_d2(k)、u_d2(k) The current and the voltage of the direct axis of the kth sampling are respectively.

4. The multi-parameter identification method of the flux linkage adjustable permanent magnet assisted synchronous reluctance motor according to claim 1, wherein the specific process of the step 3 is as follows:

step 3.1, stopping injecting the high-frequency pulse vibration magnetic linkage signal, and setting an initial value lambda of the permanent magnetic linkage_pm(i＝0)；

Step 3.2, obtaining the stator straight-axis voltage u under the steady state condition_dQuadrature axis voltage u_qStator direct axis current i_dQuadrature axis current i_qAnd a rotational speed ω_r；

Step 3.3, according to the static inductance database established in the step 1, utilizing the current permanent magnetic flux linkage lambda_pm(i) And stator direct axis current i_dQuadrature axis current i_qObtaining the static inductance L of the direct and alternating axes_d、L_q；

Step 3.4, according to the loss database established in the step 1, utilizing the current permanent magnetic flux linkage lambda_pm(i) And stator direct axis current i_dQuadrature axis current i_qObtaining direct and alternating axis loss current i_dF、i_qF；

Step 3.5, according to the direct and alternating axis loss current i_dF、i_qFStator direct axis voltage u_dQuadrature axis voltage u_qStator direct axis current i_dQuadrature axis current i_qAnd a rotational speed ω_rCalculating stator resistance R_sAnd a permanent magnetic flux linkage lambda_pm；

Step 3.6, the current permanent magnetic flux linkage lambda is determined_pm(i) And the permanent magnetic flux linkage lambda obtained by calculation in the step 3.5_pmComparing the error lambda_pm(i)-λ_pm| is less than or equal to a set allowable range λ_ΔIf so, executing step 3.9; when error | λ_pm(i)-λ_pm| is greater than the set allowable range λ_ΔIf so, executing step 3.7;

step 3.7, increasing the iteration count i to i + 1;

step 3.8, setting the permanent magnetic linkage as a calculated value lambda_pm(i)＝λ_pmReturning to the step 3.2;

and 3.9, finishing the iteration process and calculating values of the stator resistance and the permanent magnet flux linkage.

5. The method of claim 4, wherein the stator resistance R is a resistance of the permanent magnet synchronous reluctance machine_sThe calculation formula is as follows:

permanent magnet flux linkage lambda_pmThe calculation formula is as follows:

6. the multi-parameter identification method of the flux linkage adjustable permanent magnet assisted synchronous reluctance motor according to claim 1, wherein the specific process of the step 4 is as follows:

step 4.1, acquiring temperature physical characteristics of permanent magnets with different coercive forces, and establishing a data table lambda of a permanent magnet flux linkage and temperature of the permanent magnet flux linkage-temperature data table lambda as LUT _ T (T);

step 4.2, measuring the temperature T of the stator winding before working₀Combining the initial time high frequency equivalent resistance R provided in step 2_eqh(0) And the initial moment stator resistance R provided in step 3_s(0) Obtaining an initial value R of the equivalent resistance of the rotor_reqh(0) And an initial value of rotor temperature T_r0；

R_reqh(0)＝R_eqh(0)-R_s(0)

T_r0＝T₀

Step 4.3, combining the t-time high-frequency equivalent resistance R provided in step 2_eqh(t) and the stator resistance R at time t provided in step 3_s(t) calculating the equivalent resistance R of the rotor under the injection of the high-frequency signal_reqh(T) and rotor temperature T_r；

R_reqh(t)＝R_eqh(t)-R_s(t)

Wherein, alpha is the temperature coefficient of the equivalent resistance of the rotor;

step 4.4, calculating the permanent magnet flux linkage lambda of the high-coercivity permanent magnet according to the temperature characteristic of the high-coercivity permanent magnet and the rotor temperature provided in the step 4.3_HCF＝LUT_T(T_r)；

Step 4.5, according to the permanent magnetic linkage lambda with high coercive force_HCFSeparating out permanent magnetic flux linkage lambda with low coercive force_LCF：

λ_LCF＝λ_pm-λ_HCF

Wherein λ is_pmIs a permanent magnetic linkage.

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