阅读说明：本技术 基于电压矢量作用时间调节的三相电机直接转矩控制方法 (Three-phase motor direct torque control method based on voltage vector action time adjustment ) 是由 马建辉 朱孟美 慕永云 周广旭 高佳 宋宁冉 郭磊 于 2021-07-23 设计创作，主要内容包括：本公开提供了一种基于电压矢量作用时间调节的三相电机直接转矩控制方法,包括以下步骤：包括以下步骤：通过电机直接转矩控制的调节周期和在单个调节周期内电压矢量的有效作用时间,计算电压矢量占空比；基于电机磁链圆将电压矢量分成三组,结合磁链矢量幅值参考值和磁链调节强度,对每组电压矢量研究,得到电压矢量占空比为定值1时磁链矢量幅值变化量绝对值与电机磁链矢量角度之间的关系式；利用磁链滞环宽度、磁链调节强度和磁链矢量幅值参考值之间的关系,得到电压矢量占空比和电机磁链矢量角度之间的表达式,得到单个调节周期内电压矢量的有效作用时间,实现对电机的直接转矩控制。(The invention provides a direct torque control method of a three-phase motor based on voltage vector action time adjustment, which comprises the following steps: the method comprises the following steps: calculating the duty ratio of the voltage vector according to the regulation period of direct torque control of the motor and the effective acting time of the voltage vector in a single regulation period; dividing the voltage vectors into three groups based on a motor flux linkage circle, and researching each group of voltage vectors by combining a flux linkage vector amplitude reference value and flux linkage adjustment strength to obtain a relational expression between an absolute value of flux linkage vector amplitude variation and a motor flux linkage vector angle when the voltage vector duty ratio is a fixed value 1; and obtaining an expression between the duty ratio of the voltage vector and the flux linkage vector angle of the motor by utilizing the relationship among the flux linkage hysteresis width, the flux linkage adjusting strength and the flux linkage vector amplitude reference value, obtaining the effective acting time of the voltage vector in a single adjusting period, and realizing the direct torque control of the motor.)

1. The direct torque control method of the three-phase motor based on voltage vector action time adjustment is characterized by comprising the following steps of:

calculating the duty ratio of the voltage vector according to the regulation period of direct torque control of the motor and the effective acting time of the voltage vector in a single regulation period;

dividing the voltage vectors into three groups based on a motor flux linkage circle, and researching each group of voltage vectors by combining a flux linkage vector amplitude reference value and flux linkage adjustment strength to obtain a relational expression between an absolute value of flux linkage vector amplitude variation and a motor flux linkage vector angle when the voltage vector duty ratio is a fixed value 1;

and obtaining an expression between the duty ratio of the voltage vector and the flux linkage vector angle of the motor by utilizing the relationship among the flux linkage hysteresis width, the flux linkage adjusting strength and the flux linkage vector amplitude reference value, obtaining the effective acting time of the voltage vector in a single adjusting period, and realizing the direct torque control of the motor.

2. The method of direct torque control for a three phase motor based on voltage vector on-time regulation according to claim 1 wherein the voltage vector duty cycle is the percentage of the effective on-time of the voltage vector relative to the regulation period of direct torque control of the motor within a single regulation period.

3. The direct torque control method for a three-phase motor based on voltage vector on-time regulation according to claim 1, wherein the motor is divided into six sectors and six voltage vectors based on a 360-degree setting of a flux circle of the motor, the six voltage vectors are divided into three groups with the first power vector and the fourth voltage vector as a first group, the second voltage vector and the fifth voltage vector as a second group, and the third voltage vector and the sixth voltage vector as a third group.

4. The method for direct torque control of a three-phase motor based on voltage vector on-time regulation according to claim 1, wherein the magnitude of the flux linkage regulation intensity is related to the regulation period of the motor bus voltage and the direct torque control of the motor.

5. Method for direct torque control of a three-phase motor based on voltage vector function time regulation according to claim 1, characterized in that the voltage vector duty cycle Du is set to 1 with ψ_refIndicating the reference value of the amplitude of the flux linkage vector by psi_sIndicating the strength of flux linkage adjustment by U_dcRepresenting motor bus voltage by T_sIndicating the regulation period of the direct torque control of the motor by psi_incRepresenting the absolute value of the amplitude variation of the flux linkage vector, and representing the angle of the flux linkage vector by delta, then

6. Method for direct torque control of a three-phase motor based on voltage vector function time regulation according to claim 5, characterized by using ψ_bandRepresenting half of the flux linkage hysteresis width, the flux linkage adjusting strength and the flux linkage vector amplitude reference value are satisfied

7. The direct torque control method of a three-phase motor based on voltage vector acting time adjustment as claimed in claim 6, characterized in that the expression between the voltage vector duty ratio and the motor flux vector angle is obtained according to the relationship between flux hysteresis width, flux adjustment strength and flux vector magnitude reference value, and the effective acting time of the voltage vector in a single adjustment period is obtained by calculating the voltage vector duty ratio according to the current flux vector angle of the motor.

8. The three-phase motor direct torque control system based on voltage vector action time adjustment adopts the three-phase motor direct torque control method based on voltage vector action time adjustment, which is characterized by comprising a voltage vector duty ratio generation module, a flux linkage vector amplitude variation absolute value calculation module and a motor direct torque control module, wherein:

the voltage vector duty ratio generation module calculates the voltage vector duty ratio through the regulation period of direct torque control of the motor and the effective acting time of a voltage vector in a single regulation period;

the flux linkage vector amplitude variation absolute value calculation module divides voltage vectors into three groups according to a motor flux linkage circle, and researches each group of voltage vectors by combining a flux linkage vector amplitude reference value and flux linkage adjusting strength to obtain a relational expression between the flux linkage vector amplitude variation absolute value and a motor flux linkage vector angle when the voltage vector duty ratio is a fixed value 1;

the direct torque control module of the motor obtains an expression between a voltage vector duty ratio and a motor flux vector angle by utilizing the relationship among flux hysteresis width, flux adjustment strength and flux vector amplitude reference values, obtains the effective acting time of a voltage vector in a single adjustment period, and realizes the direct torque control of the motor.

9. A computer readable storage medium, on which a program is stored, which program, when being executed by a processor, is adapted to carry out the steps of the method for direct torque control of a three-phase electric machine based on voltage vector function time regulation according to any one of claims 1-7.

10. An electronic device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor when executing the program implements the steps in the method for direct torque control of a three-phase motor based on voltage vector on-time regulation according to any of claims 1-7.

Technical Field

The disclosure belongs to the technical field of motor control, and particularly relates to a direct torque control method of a three-phase motor based on voltage vector action time adjustment.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

In the field of motor Control, Direct Torque Control (DTC) is a commonly used Control algorithm, the Torque of a three-phase motor is controlled through a frequency converter, a flux hysteresis and a Torque hysteresis are designed based on a flux circle idea, and the flux is adjusted through a voltage vector so as to adjust the Torque. In the basic DTC method for the three-phase motor, six sectors and six voltage vectors are set aiming at a 360-degree space of a flux linkage circle, hysteresis comparison is carried out on an actual flux linkage vector amplitude and an actual torque, a reference flux linkage vector amplitude and a reference torque, a proper voltage vector is selected according to a predetermined switching table by combining the sector where the flux linkage vector is located, the on-off of a switching tube of a power conversion circuit is controlled, the increase and decrease of the flux linkage and the torque are adjusted, and real-time tracking of the flux linkage and the torque of the motor on a reference value is realized.

According to the inventor, the space span of each sector in the basic DTC method is 60 degrees, when flux linkage vectors are located at different positions of the same sector, due to different included angles between voltage vectors and flux linkage vectors, under the same action time, the regulation action of the voltage vectors on the flux linkage vectors is inconsistent, flux linkage overshoot is easily caused at certain positions, and the oscillation of the flux linkage and torque is increased.

Therefore, in order to control the flux linkage vector of the motor and realize the tracking control of the flux linkage and the torque of the motor, intensive research needs to be carried out on the direct torque control of the motor.

Disclosure of Invention

In order to solve the problems, the method for controlling the direct torque of the three-phase motor based on voltage vector acting time adjustment is provided by the disclosure, the angle of the current flux linkage vector is used as an independent variable, the voltage vector acting time in a duty ratio form is used as a dependent variable, the voltage vector duty ratio is calculated according to the angle of the flux linkage vector, and the flux linkage of the motor is adjusted quantitatively, so that the increment or decrement of the flux linkage vector amplitude in a single adjustment period is approximately less than or equal to half of the width of a hysteresis loop of the flux linkage, the flux linkage vector is limited in the hysteresis loop, and a better flux linkage and torque tracking effect is realized.

According to some embodiments, a first aspect of the present disclosure provides a method for controlling direct torque of a three-phase motor based on voltage vector acting time adjustment, which adopts the following technical solutions:

the direct torque control method of the three-phase motor based on the voltage vector action time adjustment specifically comprises the following steps:

calculating the duty ratio of the voltage vector according to the regulation period of direct torque control of the motor and the effective acting time of the voltage vector in a single regulation period;

dividing the voltage vectors into three groups based on a motor flux linkage circle, and researching each group of voltage vectors by combining a flux linkage vector amplitude reference value and flux linkage adjustment strength to obtain a relational expression between an absolute value of flux linkage vector amplitude variation and a motor flux linkage vector angle when the voltage vector duty ratio is a fixed value 1;

and obtaining an expression between the duty ratio of the voltage vector and the flux linkage vector angle of the motor by utilizing the relationship among the flux linkage hysteresis width, the flux linkage adjusting strength and the flux linkage vector amplitude reference value, obtaining the effective acting time of the voltage vector in a single adjusting period, and realizing the direct torque control of the motor.

According to some embodiments, a second aspect of the present disclosure provides a three-phase motor direct torque control system based on voltage vector acting time adjustment, which adopts the three-phase motor direct torque control method based on voltage vector acting time adjustment provided in the first aspect, and adopts the following technical solutions:

three-phase motor direct torque control system based on voltage vector action time regulation includes:

the voltage vector duty ratio generation module is used for calculating the voltage vector duty ratio through the regulation period of direct torque control of the motor and the effective acting time of a voltage vector in a single regulation period;

the flux linkage vector amplitude variation absolute value calculation module divides the voltage vectors into three groups according to a motor flux linkage circle, and researches each group of voltage vectors by combining a flux linkage vector amplitude reference value and flux linkage adjusting strength to obtain a relational expression between the flux linkage vector amplitude variation absolute value and a motor flux linkage vector angle when the voltage vector duty ratio is a fixed value 1;

and the motor direct torque control module obtains an expression between a voltage vector duty ratio and a motor flux vector angle by utilizing the relationship among the flux hysteresis width, the flux adjustment strength and the flux vector amplitude reference value, obtains the effective acting time of a voltage vector in a single adjustment period, and realizes the direct torque control of the motor.

A third aspect of the disclosure provides a computer-readable storage medium.

A computer readable storage medium having stored thereon a program which, when executed by a processor, implements the steps in a method of direct torque control of a three-phase motor based on voltage vector on-time regulation according to a first aspect of the present disclosure.

A fourth aspect of the present disclosure provides an electronic device.

An electronic device comprising a memory, a processor and a program stored on the memory and executable on the processor, the processor implementing the steps of the method for direct torque control of a three-phase motor based on voltage vector on-time regulation according to the first aspect of the present disclosure when executing the program.

Compared with the prior art, the beneficial effect of this disclosure is:

1. the method establishes an analytical expression between the action time of the voltage vector and the flux linkage vector angle, can limit the flux linkage vector in a hysteresis loop through simple calculation and adjustment, and improves the torque ripple suppression effect of the basic DTC;

2. the voltage vector action time calculated by the approximate expression can meet the precision requirement of engineering application, and the main realization of a basic DTC is not changed;

3. the voltage vector duty ratio in the disclosure can directly correspond to the duty ratio of the PWM module, and is simple and practical.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure and are not to limit the disclosure.

Fig. 1 is a flowchart of a method for controlling direct torque of a three-phase motor based on voltage vector acting time adjustment according to a first embodiment of the disclosure;

FIG. 2 is a DTC flux linkage vector sector and voltage vector distribution diagram in accordance with a first embodiment of the present disclosure;

FIG. 3 is a block diagram of a DTC system according to a first embodiment of the present disclosure;

FIG. 4 is a schematic diagram illustrating flux linkage vector adjustment in a first embodiment of the disclosure;

FIG. 5 is a waveform diagram illustrating an absolute value of a magnitude change of a flux linkage vector when a voltage vector is in a first group according to an embodiment of the disclosure;

FIG. 6 is a waveform diagram of the absolute value of the magnitude change of the flux linkage vector when the voltage vector is in the second group according to the first embodiment of the disclosure;

FIG. 7 is a waveform diagram of the absolute value of the magnitude change of the flux linkage vector when the voltage vector is in the third group according to the first embodiment of the disclosure;

fig. 8 is a structural diagram of a three-phase motor direct torque control system based on voltage vector action time adjustment in the second embodiment of the present disclosure.

The specific implementation mode is as follows:

the present disclosure is further described with reference to the following drawings and examples.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict.

Example one

The embodiment of the disclosure provides a direct torque control method of a three-phase motor based on voltage vector action time adjustment.

As shown in fig. 1, fig. 2, fig. 3 and fig. 4, the method for controlling the direct torque of the three-phase motor based on the voltage vector action time adjustment specifically comprises the following steps:

step S01: calculating the duty ratio of the voltage vector according to the regulation period of direct torque control of the motor and the effective acting time of the voltage vector in a single regulation period;

step S02: dividing the voltage vectors into three groups based on a motor flux linkage circle, and researching each group of voltage vectors by combining a flux linkage vector amplitude reference value and flux linkage adjustment strength to obtain a relational expression between an absolute value of flux linkage vector amplitude variation and a motor flux linkage vector angle when the voltage vector duty ratio is a fixed value 1;

step S03: and obtaining an expression between the duty ratio of the voltage vector and the flux linkage vector angle of the motor by utilizing the relationship among the flux linkage hysteresis width, the flux linkage adjusting strength and the flux linkage vector amplitude reference value, obtaining the effective acting time of the voltage vector in a single adjusting period, and realizing the direct torque control of the motor.

As one or more implementations, in step S01, the voltage vector duty cycle Du is the effective active time T of the voltage vector within a single regulation period_eRegulation period T relative to direct torque control of an electric machine_sIn percent of, i.e.

In one or more embodiments, in step S02, the motor is divided into six sectors and six voltage vectors based on a 360 ° setting of the motor flux circle to generate the first power vector V₁And a fourth voltage vector V₄As a first group with a second voltage vector V₂And a fifth voltage vector V₅As a second group with a third voltage vector V₃And a sixth voltage vector V₆As a third group, the six voltage vectors are divided into three groups, using_refIndicating the reference value of the amplitude of the flux linkage vector by psi_sIndicating the strength of flux linkage adjustment by U_dcRepresenting motor bus voltage by T_sIndicating the regulation period of the direct torque control of the motor by psi_incRepresenting the absolute value of the amplitude variation of the flux linkage vector, and representing the flux linkage vector angle by delta;

when the voltage vector is in the first group, the absolute value of the magnitude change of the flux linkage vector is psi_incThe expression between the flux linkage vector angle delta is approximated as

The absolute value ψ of the magnitude change of the flux linkage vector when the voltage vector is in the second group_incThe expression between the flux linkage vector angle delta is approximated as

When the voltage vector is in the third group, the absolute value of the variation of the magnetic linkage vector amplitudeψ_incThe expression between the flux linkage vector angle delta is approximated as

By psi_bandRepresents half of the flux hysteresis width, in this embodiment, the flux hysteresis width ψ_bandMagnetic linkage adjusting strength psi_sAnd flux linkage vector magnitude reference value psi_refThe following relationships are required to be satisfied:

on the basis of satisfying the formula (5), the strength is adjusted due to the magnetic linkageBy substituting them into equations (2), (3) and (4), respectively, there is a flux linkage vector magnitude change absolute value ψ when the voltage vector is in the first group_incThe simplified expression between the flux linkage vector angle delta is approximated as

When equation (5) is satisfied, the numerator in equation (6) is approximately 2 ψ_refψ_ssin (delta + pi/3), denominator of approximately 2 psi_refEquation (6) can be transformed into

The absolute value ψ of the magnitude change of the flux linkage vector when the voltage vector is in the second group_incThe simplified expression between the flux linkage vector angle delta is approximated as

When equation (5) is satisfied, the numerator in equation (8) is approximately 2 ψ_refψ_ssin (delta), denominator approximately 2 psi_refEquation (8) can be transformed into

When the voltage vector is in the third group, the absolute value ψ of the magnitude change of the flux linkage vector_incThe simplified expression between the flux linkage vector angle delta is approximated as

When equation (5) is satisfied, the numerator in equation (8) is approximately 2 ψ_refψ_ssin (delta +2pi/3), denominator of approximately 2 psi_refEquation (8) can be transformed into

In one or more embodiments, in step S03, in conjunction with equation (5), the method will includeIs marked as K, willIs marked as theta_cWhen the voltage vector is in the first group, in combination with equations (2), (6) and (7), the approximate simplified expression between the voltage vector duty cycle Du and the flux linkage vector angle δ is:

when the voltage vector is in the second group, in combination with equation (3), equation (8), and equation (9), the approximate simplified expression between the voltage vector duty cycle Du and the flux linkage vector angle δ is:

when the voltage vector is in the third group, in combination with equations (4), (10) and (11), the approximate simplified expression between the voltage vector duty cycle Du and the flux linkage vector angle δ is:

from equation (1), the effective active time T of the voltage vector during a regulation period_eIs T_e＝T_sDu, by combining equations (12), (13) and (14), the relationship between the effective acting time of the voltage vector and the flux linkage vector angle can be obtained, and the flux linkage vector is limited within the flux linkage hysteresis loop by simple calculation and adjustment, thereby achieving improvement in torque ripple suppression of the basic DTC of the motor.

In this embodiment, the voltage vector duty Du is set to 1,Will be provided withψ_refWhen the voltage vector is respectively located in the first group, the second group and the third group, the absolute value ψ of the flux linkage vector amplitude variation corresponding to the formula (2) and the formula (7), the formula (3) and the formula (9), and the formula (4) and the formula (11) is 0.5Wb_incThe waveform diagrams of (a) are shown in fig. 5, fig. 6 and fig. 7, respectively, wherein formula (7), formula (9) and formula (11) correspond to the dot diagrams in the diagrams, respectively.

Example two

The embodiment provides a three-phase motor direct torque control system based on voltage vector action time adjustment based on the three-phase motor direct torque control method based on voltage vector action time adjustment in the first embodiment.

A three-phase motor direct torque control system based on voltage vector action time adjustment as shown in fig. 8, comprising:

the voltage vector duty ratio generation module is used for calculating the voltage vector duty ratio through the regulation period of direct torque control of the motor and the effective acting time of a voltage vector in a single regulation period;

the flux linkage vector amplitude variation absolute value calculation module divides the voltage vectors into three groups according to a motor flux linkage circle, and researches each group of voltage vectors by combining a flux linkage vector amplitude reference value and flux linkage adjusting strength to obtain a relational expression between the flux linkage vector amplitude variation absolute value and a motor flux linkage vector angle when the voltage vector duty ratio is a fixed value 1;

and the motor direct torque control module obtains an expression between a voltage vector duty ratio and a motor flux vector angle by utilizing the relationship among the flux hysteresis width, the flux adjustment strength and the flux vector amplitude reference value, obtains the effective acting time of a voltage vector in a single adjustment period, and realizes the direct torque control of the motor.

The detailed steps of the direct torque control system of the three-phase motor based on the voltage vector action time adjustment for performing the direct torque control of the motor are the same as the motor torque control method provided by the first embodiment for adjusting the voltage vector action time, and are not described again here.

EXAMPLE III

A third embodiment of the present disclosure provides a computer-readable storage medium, on which a program is stored, where the program, when executed by a processor, implements the steps in the method for controlling direct torque of a three-phase motor based on voltage vector action time adjustment according to the first embodiment of the present disclosure.

The detailed steps are the same as those of the method for controlling the direct torque of the three-phase motor based on the voltage vector action time adjustment provided in the first embodiment, and are not described herein again.

Example four

The fourth embodiment of the present disclosure provides an electronic device, which includes a memory, a processor, and a program stored in the memory and executable on the processor, and when the processor executes the program, the processor implements the steps in the method for controlling direct torque of a three-phase motor based on voltage vector action time adjustment according to the first embodiment of the present disclosure.

The detailed steps are the same as those of the method for controlling the direct torque of the three-phase motor based on the voltage vector action time adjustment provided in the first embodiment, and are not described herein again.

Although the present disclosure has been described with reference to specific embodiments, it should be understood that the scope of the present disclosure is not limited thereto, and those skilled in the art will appreciate that various modifications and changes can be made without departing from the spirit and scope of the present disclosure.