阅读说明：本技术 一种永磁辅助同步磁阻电机的控制方法 (Control method of permanent magnet auxiliary synchronous reluctance motor ) 是由 柴璐军 张瑞峰 杨高兴 秦小霞 蔡晓 詹哲军 于 2020-12-25 设计创作，主要内容包括：本发明属于永磁辅助同步磁阻电机,涉及电机的控制方法,具体为一种永磁辅助同步磁阻电机的控制方法,解决永磁辅助同步磁阻电机输出的转矩脉动大以及现有控制策略要实时考虑L-d、L-q、ψ-f的变化才能确保输出转矩的精度的技术问题,本发明同时考虑了电机温度变化和电机饱和效应对永磁辅助同步磁阻电机参数的影响,通过查询交直轴磁链ψ-d、ψ-q提高了电机在每个工作点参数的准确性,本控制方法使得永磁辅助同步磁阻电机在宽泛的环境条件下依旧能保持高的控制精度；本发明所述的控制方法可通过抑制电机电流中的主要次谐波含量来降低电机输出的转矩脉动,提高转矩输出的平稳性,可解决永磁辅助同步磁阻电机运行时转矩脉动大的固有缺陷。(The invention belongs to a permanent magnet auxiliary synchronous reluctance motor, relates to a control method of a motor, in particular to a control method of a permanent magnet auxiliary synchronous reluctance motor, and solves the problems that the torque pulsation output by the permanent magnet auxiliary synchronous reluctance motor is large and the existing control strategy needs to consider L in real time d 、L q 、ψ f The invention considers the influence of the temperature change of the motor and the saturation effect of the motor on the parameter of the permanent magnet auxiliary synchronous reluctance motor and inquires the AC-DC axis magnetic linkage psi d 、ψ q Improves the operation of the motor at each timeThe accuracy of the point parameters is high, and the control method ensures that the permanent magnet auxiliary synchronous reluctance motor can still keep high control precision under wide environmental conditions; the control method can reduce the torque pulsation output by the motor by inhibiting the content of the main subharmonic in the current of the motor, improve the stability of torque output and solve the inherent defect of large torque pulsation when the permanent magnet auxiliary synchronous reluctance motor runs.)

1. A control method of a permanent magnet auxiliary synchronous reluctance motor is characterized in that a temperature sensor, a current sensor, a rotary transformer, a Clark conversion module, a Park conversion module, a torque instruction processing module, an MTPA table look-up module, an AC-DC axis flux linkage table look-up module, a voltage calculation module, a harmonic current suppression module and a pulse modulation module are adopted;

the temperature sensor is fixed on a stator of the permanent magnet auxiliary synchronous reluctance motor and used for acquiring the stator temperature T of the permanent magnet auxiliary synchronous reluctance motor in real time;

the current sensor is used for collecting two-phase current i of the permanent magnet auxiliary synchronous reluctance motor_aAnd i_b；

The rotary transformer is used for acquiring the rotor position theta of the permanent magnet auxiliary synchronous reluctance motor, and the rotor position theta is differentiated to obtain the rotating speed w of the permanent magnet auxiliary synchronous reluctance motor_e；

Two-phase current i of permanent magnet auxiliary synchronous reluctance motor_aAnd i_bObtaining stator current i after the processing of a Clark conversion module_αAnd i_βStator current i_αAnd i_βThe current i under the d-q rotating coordinate system is obtained after the processing of the Park transformation module_d、i_q；

The input of the torque command processing module is a target torque T_e，T_eTarget torque T from vehicle control unit VCU_eAfter amplitude limiting and torque slope processing of the torque instruction processing module, given torque T is obtained_e*；

Given torque T_eInputting the MTPA table look-up module, and outputting a direct axis instruction current i after the MTPA table look-up module is processed according to a calibrated maximum torque current ratio strategy^* _dAnd quadrature axis command current i^* _q；

The input of the quadrature-direct axis flux linkage look-up table module is a direct axis instruction current i^* _dQuadrature axis command current i^* _qAnd the stator temperature T of the motor by commanding a current i based on the direct axis^* _dQuadrature axis command current i^* _qAnd the motor stator temperature T executes a table lookup interpolation algorithm in real time, and firstly, the following value i is obtained^* _dAnd i^* _qVariable direct axis flux linkageAnd cross axis magnetic linkageSecondly, the flux linkage value is obtained based on real-time motor temperature lookupAndand namely the output of the quadrature-direct axis flux linkage table look-up module;

the voltage calculation module consists of a front feed voltage module and a current regulator module; the input of the front feed voltage module isAnd w_e(ii) a The output of the feed-forward voltage module is u_dfwAnd u_qfw(ii) a Neglecting the electronic resistance u_dfwAnd u_qfwThe formula (2) is shown in formula (1):

the input of the current regulator module isi_dAnd i_qThe output of the current regulator module is Delaut_dAnd Δ u_q；And i_dForming a first closed loop PI regulationThe output of the first closed-loop PI regulator is Delauu_d，And i_qForming a second closed-loop PI regulator with output of Delauu_q；

The output of the voltage calculation module is a direct-axis instruction voltage u_dAnd quadrature axis command voltage u_qThe calculation formula is shown in the following formula (2):

the input of the harmonic current suppression module is i^* _d5th、i^* _q5th、i^* _d7th、i^* _q7th、i_d5th、i_q5th、i_d7thAnd i_q7th(ii) a The output of the harmonic current suppression module is u_a5-7th、u_b5-7th、u_c5-7th(ii) a The harmonic current suppression module comprises a current extraction module, a current harmonic suppression regulation module and a voltage conversion module;

the control method adopts feedforward decoupling control, corresponding harmonic voltage components are injected into three-phase voltage to counteract harmonic waves in motor current, 5-order and 7-order harmonic content is obtained through fast Fourier transform, three-phase current during the running of the permanent magnet auxiliary synchronous reluctance motor is obtained through a current extraction module, Clark and Park transformation is firstly carried out under 5-order and 7-order synchronous rotation coordinates, then alternating current signals in direct current signals are filtered through a low-pass filter, and i is extracted_d5th、i_q5th、i_d7th、i_q7thA signal;

will i_d5th、i_q5th、i_d7th、i_q7thThe signal is used as a feedback link and input into a current harmonic suppression and regulation module, and the current harmonic suppression and regulation module outputs a corresponding harmonic voltage component u_d5th、u_q5th、u_d7th、u_q7thSince the 5 th and 7 th harmonic currents are expected to be zero, the current harmonics are suppressedGiven of a regulator^* _d5th、i^* _q5th、i^* _d7th、i^* _q7th0, the current harmonic suppression regulator is calculated as u by the following formula_d5thAnd u_q5th、u_d7thAnd u_q7thThe respective formulas (3) and (4) are as follows:

in the formula k_pd5th、k_pq5th、k_id5th、k_iq5thRespectively, the control parameters of the 5 th harmonic current suppression module, the values of which are adjusted according to engineering experience, wherein k is_pd7th、k_pq5th、k_id7th、k_iq7thControl parameters of the 7 th harmonic current suppression modules are respectively, and the values of the control parameters are adjusted according to engineering experience;

u_d5th、u_q5thand u_d7th、u_q7thThe voltage conversion module is used for respectively carrying out reverse Clark conversion and reverse Park conversion and then overlapping to generate u_a5-7th、u_b5-7th、u_c5-7th；

The input to the pulse modulation module is u_a*、u_bSum of u_c*，u_a*、u_bSum of u_cIs u_d、u_qU, output after inverse Park and inverse Clark conversion_a、u_b、u_cOutput u of superimposed harmonic current suppression module_a5-7th、u_b5-7th、u_c5-7thGenerating; the output of the pulse modulation module is the conduction time T of the three-phase inverter bridge IGBT_a、T_bAnd T_cAnd the IGBT is conducted to drive the motor to run.

2. The permanent magnet assisted synchronous reluctance machine according to claim 1The MTPA table look-up module is used for calibrating the MTPA table in the MTPA table look-up module, and the method comprises the step of calibrating each current amplitude i_sSetting i_sHas an interval of [0, i_max]，i_maxThe interval of the current vector angle beta is [90 DEG, 180 DEG ] for the maximum phase current of the motor]，i_sIs set to 0.25 times i_maxThe step size of the current vector angle β is set to 1 °, for each i_sCalculate i according to equation (5)^* _dAnd i^* _q：

Giving different d and q axis currents i by an upper computer^* _dAnd i^* _qRespectively adjusting PI parameters of a first closed-loop PI regulator and a second closed-loop PI regulator, and recording T after d-axis and q-axis currents achieve good follow_eAnd the output value u of the voltage calculation module_dAnd u_q(ii) a Find each i_sThe following different combinationsMaximum value T of corresponding torque_emaxThen from each i_sCorresponding T_emaxValue fitting maximum torque current ratio curve, and constructing T_emaxAre respectively connected withThe one-dimensional table is written in the program in the form of a one-dimensional array and is used as the table look-up basis of the MTPA module.

3. The method for controlling the permanent magnet-assisted synchronous reluctance motor according to claim 1, wherein the method for acquiring the temperature T of the stator of the permanent magnet-assisted synchronous reluctance motor comprises the following steps: firstly, under the environment of a drag test, a permanent magnet auxiliary synchronous reluctance motor is enabled to operate at a rated rotating speed, a tested motor is loaded, a temperature sensor tests the temperature of a motor winding or an iron core as an inductance environment temperature, a test is carried out every time the motor rises by 10 ℃ in the range of (-20 ℃) and 160 ℃, when the temperature value of the motor is stable, the recorded temperature is the temperature T of a stator of the permanent magnet auxiliary synchronous reluctance motor, and nineteen test temperature points are obtained in the range of (-20 ℃) and 160 ℃.

4. The method of claim 3, wherein the quadrature axis flux linkage table is obtained by a bench test, wherein the table is obtained by the following method: at each test temperature point, different d-axis currents i are given through an upper computer_dAnd q-axis current i_qRespectively adjusting PI parameters of a first closed-loop PI regulator and a second closed-loop PI regulator when d-axis current i_dAnd q-axis current i_qAchieving good follow-up, recording T_eAnd the output value u of the voltage calculation module_dAnd u_qThen, R is calculated by the formula (6)_s、ψ_d、ψ_qThe formula (6) is specifically:

recording the parameters obtained by the test, and respectively drawing psi_d、ψ_qAbout d-axis current i_dAnd q-axis current i_qFor each test temperature point, there is a phi_dTwo-dimensional table of and a_qA two-dimensional table of (1); a plurality of psi_d、ψ_qThe two-dimensional table is written in the program in the form of a two-dimensional array for table lookup.

5. The control method of the permanent magnet-assisted synchronous reluctance motor according to claim 4, wherein the quadrature-direct axis flux linkage parameter table look-up method is as follows; the temperature sensor collects the temperature T of the stator in real time, and each temperature T collected in real time corresponds to two table lookup temperatures T_sAnd T_s+10，T_sAnd T_s+10Is [ -20 deg.C, 160 deg.C]Two adjacent tests within the intervalTemperature point, T is at_s，T_s+10]One value of the interval, T_s+10And T_sHas the relationship of T_S+10＝T_S+10, wherein T_sIs an integer multiple of 10, and T_sThe value range of (A) is [ -20 ℃, 160 DEG C](ii) a For each table lookup temperature T_sAll have a psi_dAbout i_q、i_dTwo-dimensional table of (2) and a psi_qAbout i_q、i_dA two-dimensional table of (1); wherein i_q、i_dThe table lookup interval of (a) is set to 0.05 times the maximum current; at each table lookup temperature T_sLower, psi_dAnd psi_qThe real-time values of the time points are respectively output by the MTPA table look-up module at the time^* _dAnd i^* _qBased on psi_d、ψ_qThe parameter two-dimensional table is obtained by two-dimensional linear interpolation; temperature T of table lookup_s、T_s+10Two parameters psi of the d-axis flux linkage are obtained_d(i_d、i_q、T_s)、ψ_d(i_d、i_q、T_s+10) And two parameters psi of the q-axis flux linkage_q(i_d、i_q、T_s)、ψ_q(i_d、i_q、T_s+10) Then psi_d(i_d、i_q、T_s) And psi_d(i_d、i_q、T_s+10)、ψ_q(i_d、i_q、T_s) And psi_q(i_d、i_q、T_s+10) Respectively related to the temperature T according to the temperature T acquired in real time_s，T_s+10One-dimensional linear interpolation is carried out to obtain a direct axis flux linkage value psi_d(i_d、i_qT) and the quadrature axis flux linkage value psi_q(i_d、i_q、T)。

6. The method of claim 5, wherein ψ is calculated by the quadrature axis flux linkage table look-up module_d、ψ_qAnd motor parameter L_d，L_q，ψ_fThe following relationship exists, specifically formula (7):

7. the control method of the permanent magnet-assisted synchronous reluctance motor according to claim 1, wherein the harmonic numbers that can be suppressed by the harmonic current suppressing module are extended to 5, 7, 11 and 13.

8. The method of claim 1, wherein the current harmonic rejection adjustment module calculates the harmonic voltage component u_d5th、u_q5thWhen it is needed, k is first adjusted_pd5th、k_pq5thReadjust k_id5th、k_iq5th，k_pd5th、k_pq5thIs set to 1.0, k_id5th、k_iq5thIs set to 10; calculating harmonic voltage component u by current harmonic suppression regulating module_d7th、u_q7thWhen it is needed, k is first adjusted_pd7th、k_pq7thReadjust k_id7th、k_iq7th，k_pd5th、k_pq7thIs set to 1.0, k_id7th、k_iq7thIs set to 10.

9. The method as claimed in claim 1, wherein during the processing of the voltage conversion module, the angle used for the inverse Park conversion of the 5 th harmonic voltage component is-5 θ, and the angle used for the inverse Park conversion of the 7 th harmonic voltage component is 7 θ.

10. The control method of the permanent magnet-assisted synchronous reluctance motor according to claim 1, wherein the pulse modulation module adopts a multi-mode modulation strategy, specifically, asynchronous modulation is adopted when the motor frequency is [ 0-30 Hz ], synchronous modulation is adopted when the motor frequency is [ 30-62 Hz "), middle 60-degree modulation is adopted when the motor frequency is [ 62-90 Hz"), and square wave control is adopted when the motor frequency is [ 90-200 Hz ].

Technical Field

The invention belongs to a permanent magnet auxiliary synchronous reluctance motor, relates to a control method of a motor, and particularly relates to a control method of a permanent magnet auxiliary synchronous reluctance motor.

Background

Compared with a permanent magnet synchronous motor, the permanent magnet auxiliary synchronous reluctance motor can reduce the using amount of permanent magnets, remarkably reduce the counter electromotive force of the motor during high-speed operation, fully utilize the reluctance torque and be safer and more reliable during operation; meanwhile, the permanent magnet auxiliary synchronous reluctance motor has the remarkable advantages of high power density, high efficiency, wide speed regulation range, small volume, light weight and the like, and is more suitable for replacing the original asynchronous motor in the field of rail transit to be used as a traction motor of the diesel locomotive. The permanent magnet auxiliary synchronous reluctance motor has the obvious defect that the output torque ripple is large, and the suppression of the torque ripple must be considered in the control strategy of the permanent magnet auxiliary synchronous reluctance motor, so that the torque output by the motor is as stable as possible; meanwhile, due to the influence of the structural design of the motor rotor, the magnetic circuit is easier to saturate, and the quadrature-direct axis inductance value L_q、L_dSubjected to quadrature-direct axis current i_q、i_dWhile L is_q、L_dIs also obviously influenced by the temperature of the motor; rotor flux linkage psi_fIs not a constant value due to the influence of temperature and current amplitude, but is usually set as a constant value in the existing control strategy, so the existing control strategy considers L in real time_d、L_q、ψ_fTo ensure the accuracy of the output torque.

Disclosure of Invention

The invention aims to solve the problems that the output torque ripple of the permanent magnet auxiliary synchronous reluctance motor is large and the existing control strategy needs to be real-timeConsider L_d、L_q、ψ_fThe technical problem that the precision of the output torque can be ensured only by the change of the permanent magnet synchronous reluctance motor is solved, and a control method of the permanent magnet synchronous reluctance motor is provided.

The technical means for solving the technical problems of the invention is as follows: a control method of a permanent magnet auxiliary synchronous reluctance motor adopts a temperature sensor, a current sensor, a rotary transformer, a Clark conversion module, a Park conversion module, a torque instruction processing module, an MTPA table look-up module, a quadrature-direct axis flux chain table look-up module, a voltage calculation module, a harmonic current suppression module and a pulse modulation module;

the temperature sensor is fixed on a stator of the permanent magnet auxiliary synchronous reluctance motor and used for acquiring the stator temperature T of the permanent magnet auxiliary synchronous reluctance motor in real time;

the current sensor is used for collecting two-phase current i of the permanent magnet auxiliary synchronous reluctance motor_aAnd i_b；

The rotary transformer is used for acquiring the rotor position theta of the permanent magnet auxiliary synchronous reluctance motor, and the rotor position theta is differentiated to obtain the rotating speed w of the permanent magnet auxiliary synchronous reluctance motor_e；

Two-phase current i of permanent magnet auxiliary synchronous reluctance motor_aAnd i_bObtaining stator current i after the processing of a Clark conversion module_αAnd i_βStator current i_αAnd i_βThe current i under the d-q rotating coordinate system is obtained after the processing of the Park transformation module_d、i_q；

The input of the torque command processing module is a target torque T_e，T_eTarget torque T from vehicle control unit VCU_eAfter amplitude limiting and torque slope processing of the torque instruction processing module, given torque T is obtained_e*；

Given torque T_eInputting the MTPA table look-up module, and outputting a direct axis instruction current i after the MTPA table look-up module is processed according to a calibrated maximum torque current ratio strategy^* _dAnd quadrature axis command current i^* _q；

The input of the AC-DC axis magnetic linkage table look-up module is DCShaft command current i^* _dQuadrature axis command current i^* _qAnd the stator temperature T of the motor by commanding a current i based on the direct axis^* _dQuadrature axis command current i^* _qAnd the motor stator temperature T executes a table lookup interpolation algorithm in real time, and firstly, the following value i is obtained^* _dAnd i^* _qVariable direct axis flux linkageAnd cross axis magnetic linkageSecondly, the flux linkage value is obtained based on real-time motor temperature lookupAndand namely the output of the quadrature-direct axis flux linkage table look-up module;

the voltage calculation module consists of a front feed voltage module and a current regulator module; the input of the front feed voltage module isAnd w_e(ii) a The output of the feed-forward voltage module is u_dfwAnd u_qfw(ii) a Neglecting the electronic resistance u_dfwAnd u_qfwThe formula (2) is shown in formula (1):

the input of the current regulator module isi_dAnd i_qThe output of the current regulator module is Delaut_dAnd Δ u_q；And i_dForming a first closed-loop PI regulator with output of Delauu_d，And i_qForming a second closed-loop PI regulator with output of Delauu_q；

The output of the voltage calculation module is a direct-axis instruction voltage u_dAnd quadrature axis command voltage u_qThe calculation formula is shown in the following formula (2):

the input of the harmonic current suppression module is i^* _d5th、i^* _q5th、i^* _d7th、i^* _q7th、i_d5th、i_q5th、i_d7thAnd i_q7th(ii) a The output of the harmonic current suppression module is u_a5-7th、u_b5-7th、u_c5-7th(ii) a The harmonic current suppression module comprises a current extraction module, a current harmonic suppression regulation module and a voltage conversion module;

the control method adopts feedforward decoupling control, corresponding harmonic voltage components are injected into three-phase voltage to counteract harmonic waves in motor current, 5-7 harmonic content is obtained through fast Fourier transformation, three-phase current during the running of the permanent magnet auxiliary synchronous reluctance motor is obtained through a current extraction module, Clark and Park transformation is firstly carried out under 5-7 synchronous rotation coordinates, direct current can be generated under the corresponding times of coordinate system transformation due to the 5-7 harmonic current, and other subharmonic components are still alternating current after transformation, so that alternating current signals in the direct current signals can be filtered through a low-pass filter, i is extracted, and the alternating current signals in the direct current signals are extracted_d5th、i_q5th、i_d7th、i_q7thA signal;

will i_d5th、i_q5th、i_d7th、i_q7thThe signal is used as a feedback link and input into a current harmonic suppression and regulation module, and the current harmonic suppression and regulation module outputs a corresponding harmonic voltage component u_d5th、u_q5th、u_d7th、u_q7thGiven i of the current harmonic rejection regulator, since a 5, 7 th harmonic current is expected to be zero^* _d5th、i^* _q5th、i^* _d7th、i^* _q7th0, the current harmonic suppression regulator is calculated as u by the following formula_d5thAnd u_q5th、u_d7thAnd u_q7thThe respective formulas (3) and (4) are as follows:

in the formula k_pd5th、k_pq5th、k_id5th、k_iq5thRespectively, the control parameters of the 5 th harmonic current suppression module, the values of which are adjusted according to engineering experience, wherein k is_pd7th、k_pq5th、k_id7th、k_iq7thControl parameters of the 7 th harmonic current suppression modules are respectively, and the values of the control parameters are adjusted according to engineering experience;

u_d5th、u_q5thand u_d7th、u_q7thThe voltage conversion module is used for respectively carrying out reverse Clark conversion and reverse Park conversion and then overlapping to generate u_a5-7th、u_b5-7th、u_c5-7th；

The input to the pulse modulation module is u_a*、u_bSum of u_c*，u_a*、u_bSum of u_cIs u_d、u_qU, output after inverse Park and inverse Clark conversion_a、u_b、u_cOutput u of superimposed harmonic current suppression module_a5-7th、u_b5-7th、u_c5-7thGenerating; the output of the pulse modulation module is the conduction time T of the three-phase inverter bridge IGBT_a、T_bAnd T_cAnd the IGBT is conducted to drive the motor to run.

The invention simultaneously considers the influence of the temperature change of the motor and the saturation effect of the motor on the parameters of the permanent magnet auxiliary synchronous reluctance motor and inquires the AC-DC axis flux linkage psi_d、ψ_qThe accuracy of the motor at each working point parameter is improved, and the control method enables the permanent magnet auxiliary synchronous reluctance motor to still maintain high control precision under wide environmental conditions; the control method can reduce the torque pulsation output by the motor by inhibiting the content of the main subharmonic in the current of the motor, improve the stability of torque output and solve the inherent defect of large torque pulsation when the permanent magnet auxiliary synchronous reluctance motor runs; the optimization control method for the permanent magnet auxiliary synchronous reluctance motor can promote the popularization and application of the permanent magnet auxiliary synchronous reluctance motor.

Drawings

Fig. 1 is a general control block diagram of a control method of a permanent magnet-assisted synchronous reluctance motor according to the present invention.

FIG. 2 is a synchronous rotating coordinate system according to the present invention.

FIG. 3 is a table look-up flow chart of quadrature-direct axis flux linkage according to the present invention.

FIG. 4 is a control diagram of the current draw module of the present invention.

Fig. 5 is a control block diagram of the 5 th harmonic suppression adjusting module according to the present invention.

FIG. 6 is a control block diagram of the 7 th harmonic rejection regulation module of the present invention.

Fig. 7 is a block diagram of a multi-mode modulation strategy of the pulse modulation module according to the present invention.

Detailed Description

A control method of a permanent magnet assisted synchronous reluctance motor according to the present invention will be described in detail with reference to fig. 1 to 7.

A control method of a permanent magnet auxiliary synchronous reluctance motor is disclosed in figure 1, and adopts a temperature sensor, a current sensor, a rotary transformer, a Clark conversion module, a Park conversion module, a torque instruction processing module, an MTPA table look-up module, an AC-DC axis flux linkage table look-up module, a voltage calculation module, a harmonic current suppression module and a pulse modulation module;

the temperature sensor is fixed on a stator of the permanent magnet auxiliary synchronous reluctance motor and used for acquiring the stator temperature T of the permanent magnet auxiliary synchronous reluctance motor in real time; the method for acquiring the temperature T of the stator of the permanent magnet auxiliary synchronous reluctance motor comprises the following steps: firstly, under a drag test environment, a permanent magnet auxiliary synchronous reluctance motor runs at a rated rotating speed, a tested motor is loaded, a temperature sensor tests the temperature of a motor winding or an iron core as an inductance environment temperature, a test is carried out when the motor rises by 10 ℃ every time in a range of (-20 ℃) and 160 ℃, when the motor temperature value is stable, the recorded temperature is the temperature T of a stator of the permanent magnet auxiliary synchronous reluctance motor, and nineteen test temperature points are obtained in the range of (-20 ℃) and 160 ℃;

the current sensor is used for collecting two-phase current i of the permanent magnet auxiliary synchronous reluctance motor_aAnd i_b；

The rotary transformer is used for acquiring the rotor position theta of the permanent magnet auxiliary synchronous reluctance motor, and the rotor position theta is differentiated to obtain the rotating speed w of the permanent magnet auxiliary synchronous reluctance motor_e；

Two-phase current i of permanent magnet auxiliary synchronous reluctance motor_aAnd i_bObtaining stator current i after the processing of a Clark conversion module_αAnd i_βStator current i_αAnd i_βThe current i under the d-q rotating coordinate system is obtained after the processing of the Park transformation module_d、i_q；

The input of the torque command processing module is a target torque T_e，T_eTarget torque T from vehicle control unit VCU_eAfter amplitude limiting and torque slope processing of the torque instruction processing module, given torque T is obtained_e*；

Given torque T_eInput MTPA look-up table module, MTPA look-up table module according to calibrationAfter the maximum torque current ratio strategy is processed, a direct axis instruction current i is output^* _dAnd quadrature axis command current i^* _q(ii) a Specifically, the MTPA table in the MTPA table look-up module is implemented by a calibration method, which includes, for each current amplitude i_sSetting i_sHas an interval of [0, i_max]，i_maxThe interval of the current vector angle beta is [90 DEG, 180 DEG ] for the maximum phase current of the motor]，i_sIs set to 0.25 times i_maxThe step size of the current vector angle β is set to 1 °, for each i_sCalculate i according to equation (5)^* _dAnd i^* _q：

Giving different d and q axis currents i by an upper computer^* _dAnd i^* _qRespectively adjusting PI parameters of a first closed-loop PI regulator and a second closed-loop PI regulator, and recording T after d-axis and q-axis currents achieve good follow_eAnd the output value u of the voltage calculation module_dAnd u_q(ii) a Find each i_sThe following different combinationsMaximum value T of corresponding torque_emaxThen from each i_sCorresponding T_emaxValue fitting maximum torque current ratio curve, and constructing T_emaxAre respectively connected withThe one-dimensional table is written in a program in a form of a one-dimensional array and is used as a table look-up basis of the MTPA module;

the input of the quadrature-direct axis flux linkage look-up table module is a direct axis instruction current i^* _dQuadrature axis command current i^* _qAnd the stator temperature T of the motor by commanding a current i based on the direct axis^* _dQuadrature axis command current i^* _qAnd the motor stator temperature T execute a table lookup interpolation algorithm in real time, firstFirst obtain random i^* _dAnd i^* _qVariable direct axis flux linkageAnd cross axis magnetic linkageSecondly, the flux linkage value is obtained based on real-time motor temperature lookupAndandnamely the output of the quadrature-direct axis flux linkage table look-up module; the quadrature-direct axis magnetic linkage table can be obtained through a bench test, and the method for obtaining the table through the bench test is as follows: at each test temperature point, different d-axis currents i are given through an upper computer_dAnd q-axis current i_qRespectively adjusting PI parameters of a first closed-loop PI regulator and a second closed-loop PI regulator when d-axis current i_dAnd q-axis current i_qAchieving good follow-up, recording T_eAnd the output value u of the voltage calculation module_dAnd u_qThen, R is calculated by the formula (6)_s、ψ_d、ψ_qThe formula (6) is specifically:

recording the parameters obtained by the test, and respectively drawing psi_d、ψ_qAbout d-axis current i_dAnd q-axis current i_qFor each test temperature point, there is a phi_dTwo-dimensional table of and a_qA two-dimensional table of (1); a plurality of psi_d、ψ_qThe two-dimensional table is written in a program in a two-dimensional array form for table lookup; the method for looking up the AC-DC axis flux linkage parameter is as follows3: the temperature sensor collects the temperature T of the stator in real time, and each temperature T collected in real time corresponds to two table lookup temperatures T_sAnd T_s+10，T_sAnd T_s+10Is [ -20 deg.C, 160 deg.C]Two adjacent test temperature points within the interval, T being at [ T_s，T_s+10]One value of the interval, T_s+10And T_sHas the relationship of T_S+10＝T_S+10, wherein T_sIs an integer multiple of 10, and T_sThe value range of (A) is [ -20 ℃, 160 DEG C](ii) a For each table lookup temperature T_sAll have a psi_dAbout i_q、i_dTwo-dimensional table of (2) and a psi_qAbout i_q、i_dA two-dimensional table of (1); wherein i_q、i_dThe table lookup interval of (a) is set to 0.05 times the maximum current; at each table lookup temperature T_sLower, psi_dAnd psi_qThe real-time values of the time points are respectively output by the MTPA table look-up module at the time^* _dAnd i^* _qBased on psi_d、ψ_qThe parameter two-dimensional table is obtained by two-dimensional linear interpolation; temperature T of table lookup_s、T_s+10Two parameters psi of the d-axis flux linkage are obtained_d(i_d、i_q、T_s)、ψ_d(i_d、i_q、T_s+10) And two parameters psi of the q-axis flux linkage_q(i_d、i_q、T_s)、ψ_q(i_d、i_q、T_s+10) Then psi_d(i_d、i_q、T_s) And psi_d(i_d、i_q、T_s+10)、ψ_q(i_d、i_q、T_s) And psi_q(i_d、i_q、T_s+10) Respectively related to the temperature T according to the temperature T acquired in real time_s，T_s+10One-dimensional linear interpolation is carried out to obtain a direct axis flux linkage value psi_d(i_d、i_qT) and the quadrature axis flux linkage value psi_q(i_d、i_qT); in the calculation of the quadrature-direct axis flux linkage table look-up module, #_d、ψ_qAnd motor parameter L_d，L_q，ψ_fExist asThe following relationship, specifically, formula (7):

the voltage calculation module consists of a front feed voltage module and a current regulator module; the input of the front feed voltage module isAnd w_e(ii) a The output of the feed-forward voltage module is u_dfwAnd u_qfw(ii) a Neglecting the electronic resistance u_dfwAnd u_qfwThe formula (2) is shown in formula (1):

the input of the current regulator module isi_dAnd i_qThe output of the current regulator module is Delaut_dAnd Δ u_q；And i_dForming a first closed-loop PI regulator with output of Delauu_d，And i_qForming a second closed-loop PI regulator with output of Delauu_q；

The output of the voltage calculation module is a direct-axis instruction voltage u_dAnd quadrature axis command voltage u_qThe calculation formula is shown in the following formula (2):

harmonic current suppression moduleIs input of i^* _d5th、i^* _q5th、i^* _d7th、i^* _q7th、i_d5th、i_q5th、i_d7thAnd i_q7th(ii) a The output of the harmonic current suppression module is u_a5-7th、u_b5-7th、u_c5-7th(ii) a The harmonic current suppression module comprises a current extraction module, a current harmonic suppression regulation module and a voltage conversion module;

the control method adopts feed-forward decoupling control, corresponding harmonic voltage components are injected into three-phase voltage to counteract harmonic waves in motor current, high 5 and 7-order harmonic content is obtained through fast Fourier transform, a synchronous rotating coordinate system is shown in figure 2, wherein the rotating direction of the 5-order harmonic voltage is opposite to the rotating direction of fundamental wave vectors, the angular velocity is 5 times of the fundamental wave, the 7-order harmonic voltage vectors are the same as the rotating direction of the fundamental wave voltage, and the angular velocity is 7 times of the fundamental wave, in addition, permanent magnet auxiliary synchronous reluctance motors with different powers possibly contain different harmonic contents of different frequencies, and therefore, the harmonic frequency which can be inhibited by a harmonic current inhibiting module can be expanded into 5, 7, 11 and 13 times; therefore, the expression of the three-phase current containing 5 and 7 harmonics is shown as the formula (8):

in the formula (8): i₁Is the amplitude of the fundamental wave, i₅Is the amplitude of the 5 th harmonic of the current i₇Is the amplitude of the 7 th harmonic of the current, phi₁、φ₂、φ₃Respectively, initial phases;

establishing a rotating coordinate system of a harmonic component of 5 th order and a harmonic component of 7 th order, adopting equal-amplitude transformation according to the Clark and Park transformation principles, wherein the rotating direction of the rotating coordinate system is the same as that of a d-q synchronous rotating coordinate system, and the same-frequency rotating current quantity with the coordinate system is direct current quantity under the coordinate system, so that the harmonic component of 5 th order is direct current quantity under the d-q synchronous rotating coordinate system of 5 th order, and the harmonic current component of 7 th order is direct current quantity under the d-q synchronous rotating coordinate system of 7 th order;

the steady state voltage equation of the 5 th harmonic under the 5 th harmonic d-q synchronous rotation coordinate system is shown as formula (9):

u in formula (9)_d5th、u_q5thRespectively are d-axis voltage value and q-axis voltage value of 5-order harmonic voltage under 5-order synchronous coordinates, wherein i is_d5th、i_q5thD-axis current values and q-axis current values of 5-order harmonic current under 5-order synchronous coordinates are respectively obtained;

the steady state voltage equation of the 7 th harmonic under the 7 th harmonic d-q synchronous rotation coordinate system is shown as formula (10):

u in formula (10)_d7th、u_q7thRespectively representing d-axis voltage value and q-axis voltage value of 7-order harmonic voltage under 7-order synchronous coordinates, wherein i is_d7th、i_q7thD-axis current values and q-axis current values of 7-order harmonic current under 7-order synchronous coordinates are respectively obtained;

the three-phase current of the permanent magnet auxiliary synchronous reluctance motor during operation is obtained through the current extraction module, Clark and Park conversion is firstly carried out under 5-order and 7-order synchronous rotation coordinates, direct current can be generated under the corresponding-order coordinate system conversion of 5-order and 7-order harmonic currents, and the direct current is still alternating current after conversion of other subharmonic components, so that alternating current signals in the direct current signals can be filtered through the low-pass filter, i is extracted, and_d5th、i_q5th、i_d7th、i_q7thsignals, as shown in FIG. 4;

will i_d5th、i_q5th、i_d7th、i_q7thThe signal is used as a feedback link and input into a current harmonic suppression and regulation module, and the current harmonic suppression and regulation module outputs a corresponding harmonic voltage component u_d5th、u_q5th、u_d7th、u_q7thGiven i of the current harmonic rejection regulator, since a 5, 7 th harmonic current is expected to be zero^* _d5th、i^* _q5th、i^* _d7th、i^* _q7th0, the current harmonic suppression regulator is calculated as u by the following formula_d5thAnd u_q5th、u_d7thAnd u_q7thThe respective formulas (3) and (4) are as follows, and are specifically shown in fig. 5 and 6:

in the formula k_pd5th、k_pq5th、k_id5th、k_iq5thRespectively, the control parameters of the 5 th harmonic current suppression module, the values of which are adjusted according to engineering experience, wherein k is_pd7th、k_pq5th、k_id7th、k_iq7thControl parameters of the 7 th harmonic current suppression modules are respectively, and the values of the control parameters are adjusted according to engineering experience; calculating harmonic voltage component u by current harmonic suppression regulating module_d5th、u_q5thWhen it is needed, k is first adjusted_pd5th、k_pq5thReadjust k_id5th、k_iq5th，k_pd5th、k_pq5thIs set to 1.0, k_id5th、k_iq5thIs set to 10; calculating harmonic voltage component u by current harmonic suppression regulating module_d7th、u_q7thWhen it is needed, k is first adjusted_pd7th、k_pq7thReadjust k_id7th、k_iq7th，k_pd5th、k_pq7thIs set to 1.0, k_id7th、k_iq7thIs set to 10;

u_d5th、u_q5thand u_d7th、u_q7thThe voltage conversion module is used for respectively carrying out reverse Clark conversion and reverse Park conversion and then overlapping to generate u_a5-7th、u_b5-7th、u_c5-7th(ii) a The angle used by the 5-order harmonic voltage component inverse Park transformation is-5 theta, and the angle used by the 7-order harmonic voltage component inverse Park transformation is 7 theta;

the input to the pulse modulation module is u_a*、u_bSum of u_c*，u_a*、u_bSum of u_cIs u_d、u_qU, output after inverse Park and inverse Clark conversion_a、u_b、u_cOutput u of superimposed harmonic current suppression module_a5-7th、u_b5-7th、u_c5-7thGenerating; u. of_a、u_b、u_cIs the formula (11):

the output of the pulse modulation module is the conduction time T of the three-phase inverter bridge IGBT_a、T_bAnd T_cThe IGBT is conducted to drive the motor to run, and the internal combustion locomotive traction system belongs to a high-power electric transmission system and is mainly characterized by high voltage and high current, the peak power of the motor reaches 700kW and is limited by a heat dissipation condition, the switching frequency of the IGBT is only 750Hz at most, but the output frequency of an inverter can reach 200Hz, the traditional svpwm modulation algorithm cannot meet the full requirement, the modulation algorithm adopts a multi-mode modulation strategy, as shown in figure 7, specifically, asynchronous modulation is adopted when the motor frequency is [ 0-30 Hz ], synchronous modulation is adopted when the motor frequency is [ 30-62 Hz ], middle 60-degree modulation is adopted when the motor frequency is [ 62-90 Hz ], and the motor frequency is [ 90-200 Hz ]]Square wave control is used.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.