阅读说明：本技术 一种记忆电机宽速度范围调磁控制方法 (Memory motor wide speed range magnetic regulation control method ) 是由 林鹤云 仲宇翔 阳辉 吕舒康 陈智勇 房淑华 于 2021-01-13 设计创作，主要内容包括：本发明公开了一种记忆电机宽速度范围调磁控制方法,该方法接收到调磁指令时,根据当前工况,包括转速n、负载电流i-q等,计算出调磁指令所需要的最大动态电压U-(ms),选择合适的梯形波d轴充去磁电流变化率di-d/dt,使得U-(ms)在母线电压所能提供的最大相电压U-p范围内；当电流变化率di-d/dt最小,而调磁所需动态电压仍然超出母线电压时,采用改进q轴电流调节器,母线电压利用率最大化,产生的q轴电流降低了调磁所需动态电压,保证调磁的顺利进行；该种方法能够根据工况选择合适的充去磁电流变化率di-d/dt以及电流调节器,加快调磁速度,降低调磁损耗,且能够在更宽的速度范围内进行调磁。(The invention discloses a memory motor wide speed range magnetic regulation control method, which comprises the steps of rotating speed n and load current i according to the current working condition when receiving a magnetic regulation instruction q And calculating the maximum dynamic voltage U required by the magnetic regulating instruction ms Selecting proper trapezoidal wave d-axis magnetizing and demagnetizing current change rate di d Dt, so that U ms Maximum phase voltage U provided by bus voltage p Within the range; when rate of change of current di d When the voltage of the bus is maximized, the generated q-axis current reduces the dynamic voltage required by magnetic adjustment, and the smooth advance of the magnetic adjustment is ensuredA row; the method can select a proper magnetizing and demagnetizing current change rate di according to the working condition d The current regulator accelerates the magnetic regulation speed, reduces the magnetic regulation loss, and can regulate the magnetic in a wider speed range.)

1. A memory motor wide speed range magnetic adjustment control method is characterized by comprising the following steps:

s1, according to the actual motor characteristics, the tracking performance and the magnetic modulation pulse loss of the PI current regulator are integrated, and the current change rate of the isosceles trapezoid magnetic modulation current pulse is selectedAndwherein

S2, selecting the change rate of the magnetic regulating current asCalculating the maximum magnetic regulation dynamic voltage U required by executing the magnetic regulation instruction under the current rotating speed and load conditions_ms2Judgment of U_ms2Whether the bus voltage is exceeded or not, further adjusting the current change rate and selecting the most appropriate one

S3, the motor runs in a middle and low speed area, the magnetic field can be successfully adjusted by adjusting the current change rate, and the traditional double-current regulator is adopted at the moment, and the aim of minimizing the fluctuation of the rotating speed is fulfilled; the motor operates in a high-speed region even if the current change rate is at a minimumMaximum phase voltage U_pIs still less than the dynamic voltage U required by magnetic regulation_ms3And in the process, the q-axis current regulator is improved, so that the utilization rate of the bus voltage is maximized, the dynamic voltage required by magnetic regulation is reduced through the change of q-axis current, the magnetic regulation is ensured to be carried out smoothly, and the magnetic regulation rotating speed range is widened.

2. The method as claimed in claim 1, wherein in step S1,the selection of the d-axis current regulator is limited by the tracking speed of the d-axis current regulator, and the actual current can track a given reference value;the choice of (2) is limited by the flux modulation losses and the torque ripple during flux modulation.

3. The method as claimed in claim 1, wherein the step of calculating the field modulation dynamic voltage in step S2 comprises the steps of:

s2.11: measuring the maximum phase resistance R of the motor winding under different operating temperatures, different magnetization states and different loads_amaxMaximum d, q axis inductance L_dmaxAnd L_qmaxAnd storing the data into a controller;

s2.12: detecting electrical angular velocity omega of motor_eQ-axis current i_qMagnetic linkage psi before and after magnetic regulation_PM1、ψ_PM2D-axis current pulse value i required for magnetic regulation_dAnd the rate of change of current of the modulated magnetic current pulse

S2.13: from the data of S2.11 and S2.12, and assuming that the q-axis current fluctuation is small, substitute into the voltage equationIn the middle, the maximum d and q axis dynamic voltage u at the moment of magnetic regulation can be obtained_dmaxAnd u_qmaxTo further obtain the required magnetic field regulating dynamic voltage

4. The method as claimed in claim 3, wherein the current variation rate of the magnetic modulating current pulse in step S2The selection of (a) comprises the following steps:

s2.21: selectingSubstituting the initial value into a magnetic regulation dynamic voltage calculation module to obtain U_ms2；

S2.22: if U is_ms2Less than phase voltage U_pThen selectRecalculating the field modulated dynamic voltage U_ms1(ii) a If U is present_ms1Greater than U_pThen selectAs the current change rate of this time of magnetic regulation; if U is present_ms1Less than U_pThen selectAs the current change rate of this time of magnetic regulation;

s2.23: if U is_ms2Greater than phase voltage U_pThen selectRecalculating the field modulated dynamic voltage U_ms3(ii) a If U is present_ms3Less than U_pThen selectAs the current change rate of this time of magnetic regulation; if U is present_ms3Greater than U_pThen selectAnd as the current change rate of the current magnetic adjustment, the magnetic adjustment is carried out by adopting an improved q-axis current adjuster.

5. The method as claimed in claim 1, wherein in step S3, the reference value of q-axis current of the conventional dual current regulator is the output of the speed loop to reduce the speed fluctuation; in the improved q-axis current regulator, the d-axis PI regulator and the q-axis PI regulator output reference voltagesAndcalculating the phase voltage at this timeAt maximum phase voltage U_pAs a reference voltage, the actual phase voltage u_msFor feedback, the difference value passes through a PI regulator, a q-axis reference voltage is output, the utilization rate of the bus voltage is maximized at the moment, and a magnetic regulating instruction is completed through q-axis current change.

Technical Field

The invention relates to a motor control technology, in particular to a memory motor wide speed range magnetic adjustment control method.

Background

A Memory Motor (MM) is a new type of permanent magnet synchronous Motor and has attracted much attention. The motor utilizes the magnetic flux variability of the low-coercivity permanent magnet and applies current pulses to change the permanent magnet flux linkage. Therefore, when the motor operates in a high-speed region, continuous weak magnetic current is not needed, and only instantaneous current pulse is needed to reduce the permanent magnet flux linkage, so that the copper consumption is reduced.

When the memory motor adjusts the magnetism, because the bus voltage is fixed, the time of adjusting the magnetism can not be too short, the rotational speed can not be too high, has restricted the flexibility of adjusting the magnetism. At present, a learner adopts a current trajectory prediction algorithm in a low-speed area, but the condition of load is not considered; for high-speed magnetic modulation, RRCVT and SL lambda are commonly used^ST is used for widening the rotating speed range during magnetic adjustment, however, the former neglects resistance voltage drop, and the latter is not suitable for vector control.

Disclosure of Invention

The purpose of the invention is as follows: the invention provides a control method which can automatically adjust the change rate of the magnetic regulating current, namely the magnetic regulating time according to the bus voltage margin and can realize magnetic regulation in a higher speed range.

The technical scheme is as follows: a memory motor wide speed range magnetic adjustment control method comprises the following steps:

s1, according to the actual motor characteristics, the tracking performance and the magnetic modulation pulse loss of the PI current regulator are integrated, and the current change rate of the isosceles trapezoid magnetic modulation current pulse is selectedAndwherein

S2, selecting the change rate of the magnetic regulating current asCalculating the maximum magnetic regulation dynamic voltage U required by executing the magnetic regulation instruction under the current rotating speed and load conditions_ms2Judgment of U_ms2Whether the bus voltage is exceeded or not, further adjusting the current change rate and selecting the most appropriate oneUnder the limitation of bus voltage, the magnetic regulating instruction can be rapidly and successfully executed;

s3, the motor runs in a middle and low speed area, the magnetic field can be successfully adjusted by adjusting the current change rate, and the traditional double-current regulator is adopted at the moment, and the aim of minimizing the fluctuation of the rotating speed is fulfilled; the motor operates in a high-speed region even if the current change rate is at a minimumMaximum phase voltage U_pIs still less than the dynamic voltage U required by magnetic regulation_ms3And in the process, the q-axis current regulator is improved, so that the utilization rate of the bus voltage is maximized, the dynamic voltage required by magnetic regulation is reduced through the change of q-axis current, the magnetic regulation is ensured to be carried out smoothly, and the magnetic regulation rotating speed range is widened.

Further, in the step S1,the selection of the d-axis current regulator is limited by the tracking speed of the d-axis current regulator, and the actual current can track a given reference value;the choice of (2) is limited by the flux modulation losses and the torque ripple during flux modulation.

Further, the calculation of the magnetic tuning dynamic voltage in step S2 includes the following steps:

s2.11: measuring the maximum phase resistance R of the motor winding under different operating temperatures, different magnetization states and different loads_amaxMaximum d, q axis inductance L_dmaxAnd L_qmaxAnd storing the data into a controller;

s2.12: detecting electrical angular velocity omega of motor_eQ-axis current i_qMagnetic linkage psi before and after magnetic regulation_PM1、ψ_PM2D-axis current pulse value i required for magnetic regulation_dAnd the rate of change of current of the modulated magnetic current pulse

S2.13: from the data of S2.11 and S2.12, and assuming that the q-axis current fluctuation is small, substitute into the voltage equationIn the middle, the maximum d and q axis dynamic voltage u at the moment of magnetic regulation can be obtained_dmaxAnd u_qmaxTo further obtain the required magnetic field regulating dynamic voltage

Further, in the step S2, the current change rate of the magnetic modulating current pulseThe selection of (a) comprises the following steps:

s2.21: selectingSubstituting the initial value into a magnetic regulation dynamic voltage calculation module to obtain U_ms2；

S2.22: if U is_ms2Less than phase voltage U_pThen selectRecalculating the field modulated dynamic voltage U_ms1(ii) a If U is present_ms1Greater than U_pThen selectAs the current change rate of this time of magnetic regulation; if U is present_ms1Less than U_pThen selectAs the current change rate of this time of magnetic regulation;

s2.23: if U is_ms2Greater than phase voltage U_pThen selectRecalculating the field modulated dynamic voltage U_ms3(ii) a If U is present_ms3Less than U_pThen selectAs the current change rate of this time of magnetic regulation; if U is present_ms3Greater than U_pThen selectAnd as the current change rate of the current magnetic adjustment, the magnetic adjustment is carried out by adopting an improved q-axis current adjuster.

Further, in the step S3, the reference value of the q-axis current of the conventional dual current regulator is the output of the speed loop, so as to reduce the speed fluctuation; in the improved q-axis current regulator, the d-axis PI regulator and the q-axis PI regulator output reference voltagesAndcalculating the phase voltage at this timeAt maximum phase voltage U_pAs a reference voltage, the actual phase voltage u_msFor feedback, the difference value passes through a PI regulator, a q-axis reference voltage is output, the utilization rate of the bus voltage is maximized at the moment, and regulation is completed through q-axis current changeMagnetic instructions.

Has the advantages that:

1. compared with a magnetic regulation control method with fixed magnetic regulation time, the method has the advantages that the magnetic regulation is faster in a low-speed area, the magnetic regulation loss is small, and the rotation speed fluctuation is small;

2. compared with the traditional magnetic regulation control method, the method disclosed by the invention can be used for calculating the dynamic voltage required by magnetic regulation according to the current operating condition, easily judging whether the bus voltage is enough or not, and further selecting the proper magnetic regulation time;

3. compared with the traditional magnetic regulation control method, the method disclosed by the invention can complete magnetic regulation in a wider speed range, and is simple in algorithm and easy to implement.

Drawings

FIG. 1 is a block diagram of a method embodying the present invention;

FIG. 2 is a block diagram of a magnetic tuning dynamic voltage calculation module according to an embodiment of the present invention;

FIG. 3 is a graph showing the change rate di of the pulse current of the magnetic modulating current in the method of the present invention_dA flow chart of a selection algorithm of/dt;

FIG. 4 is a waveform diagram of dynamic voltage experiment of d and q axes at the moment of magnetic adjustment in the embodiment of the present invention;

FIG. 5 is a waveform diagram of the current, rotation speed and voltage experiment under the variable time magnetic adjustment algorithm in the embodiment of the invention;

fig. 6 is a waveform diagram of the magnetic moment d and q-axis current experiment under the condition of improving the q-axis current regulator in the embodiment of the invention.

Detailed Description

The embodiment provides a memory motor wide speed range magnetic modulation control method, as shown in fig. 1, the method comprises the following specific steps:

s1, selecting the current change rate of isosceles trapezoid magnetic modulation current pulse according to the tracking performance and magnetic modulation pulse loss of the PI current regulatorAndwherein

WhereinThe selection of (1) is limited by the tracking speed of a d-axis current regulator (mainly a PI regulator), and the actual current can track a given reference value;the selection of (A) is limited by the magnetic modulation loss and the torque ripple during the magnetic modulation, too smallThe magnetic regulation time is very long, the loss is large, the torque pulsation is large during the magnetic regulation, and the rotating speed is not stable.

S2, selecting the change rate of the magnetic regulating current asCalculating the maximum magnetic regulation dynamic voltage U required by executing the magnetic regulation instruction under the current rotating speed and load conditions_ms2Judgment of U_ms2Whether the bus voltage is exceeded or not, further adjusting the current change rate and selecting the most appropriate oneUnder the limitation of bus voltage, the magnetic regulating instruction can be rapidly and successfully executed;

s2.1, as shown in FIG. 2, the specific steps of the magnetic regulation dynamic voltage calculation include:

s2.11: measuring the maximum phase resistance R of the winding under different running temperatures, different magnetization states and different loads of the motor_amaxMaximum d, q axis inductance L_dmaxAnd L_qmaxAnd storing the data into a controller;

s2.12: detecting angular velocity omega of motor_eQ-axis current i_qMagnetic linkage psi before and after magnetic regulation_PM1、ψ_PM2D-axis current pulse value i required for magnetic regulation_dAnd the rate of change of current of the modulated magnetic current pulse

S2.13: from the data of S2.11 and S2.12, and assuming that the q-axis current fluctuation is small, substitute into the voltage equationIn the middle, the maximum d and q axis dynamic voltage u at the moment of magnetic regulation can be obtained_dmaxAnd u_qmaxFurther obtain the magnetic-field-adjusting dynamic voltage

FIG. 4 shows the rotation speed of 0rpm, i_qD and q axis field adjusting dynamic voltage waveform when +35A magnetizing current is applied under the condition of 0, wherein the current change rateActual required magnetic regulation dynamic electric U_ms52.37V, U obtained by a magnetic regulating voltage calculation module_{ms_pre}The error is 2 percent when the voltage is 53.63V, and the effectiveness of the magnetism regulating dynamic voltage calculation module is verified;

s2.2, current change rate of magnetic current pulseAs shown in the flow chart of fig. 3, the method mainly comprises the following steps:

s2.21: selectingSubstituting the initial value into a magnetic field regulating dynamic voltage detection module to obtain U_ms2；

S2.22: if U is_ms2Less than the bus voltage, then selectRecalculating the field modulated dynamic voltage U_ms1(ii) a If it is notU_ms1If it is greater than the bus voltage, it is selectedAs the current change rate of this time of magnetic regulation; if U is present_ms1Less than the bus voltage, then selectAs the current change rate of this time of magnetic regulation;

s2.23: if U is_ms2If it is greater than the bus voltage, it is selectedRecalculating the field modulated dynamic voltage U_ms3(ii) a If U is present_ms3Less than the bus voltage, then selectAs the current change rate of this time of magnetic regulation; if U is present_ms3If it is greater than the bus voltage, it is selectedAs the current change rate of the current magnetic adjustment, an improved q-axis current adjuster is adopted for magnetic adjustment;

s3, the motor runs in a middle and low speed area, the magnetic field can be successfully adjusted by adjusting the current change rate, and the traditional double-current regulator is adopted at the moment, and the aim of minimizing the fluctuation of the rotating speed is fulfilled; the motor operates in a high-speed region even if the current change rate is at a minimumMaximum phase voltage U_pIs still less than the dynamic voltage U required by magnetic regulation_ms3And in the process, the q-axis current regulator is improved, so that the utilization rate of the bus voltage is maximized, the dynamic voltage required by magnetic regulation is reduced through the change of q-axis current, the magnetic regulation is ensured to be carried out smoothly, and the magnetic regulation rotating speed range is widened.

The method specifically comprises the steps that a reference value of q-axis current of a traditional double-current regulator is output of a rotating speed loop, and rotating speed fluctuation is reduced; in the modified q-axis current regulator, as shown in fig. 1, the q-axis current reference value is given by the following steps:

s3.11, d, q axis PI regulator output reference voltageAndcalculating the phase voltage at this time

S3.12, maximum phase voltage U_pAs a reference voltage, the actual voltage u_msFor feedback, track U_pOutputting a q-axis reference voltage through a PI regulator, maximizing the utilization rate of bus voltage, and finishing a magnetic regulation instruction by changing a q-axis current track;

FIG. 5 is an experimental waveform obtained by using the above-mentioned magnetic tuning algorithm, and the DC bus voltage U_DCAt 120V, i.e. maximum phase voltageThe rotating speed is 500rpm, the magnetizing instruction is to apply +10A magnetizing current, and the current change rate is selected according to the magnetizing algorithmAs shown in the amplified waveform of the magnetic tuning current in fig. 5, the magnetic tuning current can well track the reference value, the magnetic tuning time is short, and the loss is small. At the moment, the fluctuation of the q-axis current is small, and the fluctuation of the rotating speed is small.

FIG. 6 shows the experimental waveforms of d-and q-axis currents with an improved q-axis current regulator, a rotation speed of 400rpm, a magnetizing current of +35A, and u in the dashed area_ms＝U_pFrom the voltage equation, it can be seen that the illustrated change in q-axis current can reduce the maximum U required for magnetic tuning_msTherefore, the magnetic adjustment is successfully completed, otherwise, the bus voltage is not enough to complete the magnetic adjustment instruction at the rotating speed, and the effectiveness of the q-axis current regulator is verified.

The invention discloses a magnetic regulation control method, which selects a proper magnetic regulation current change rate and reduces the magnetic regulation time when the low-speed area, namely the bus voltage is abundant, thereby reducing the magnetic regulation loss and the rotating speed fluctuation.