CN110932628B

CN110932628B - Pulse width modulation method and device for five-phase motor and terminal equipment

Info

Publication number: CN110932628B
Application number: CN201911287235.2A
Authority: CN
Inventors: 龙凌辉; 孙天夫
Original assignee: Shenzhen Institute of Advanced Technology of CAS
Current assignee: Shenzhen Institute of Advanced Technology of CAS
Priority date: 2019-12-14
Filing date: 2019-12-14
Publication date: 2021-07-09
Anticipated expiration: 2039-12-14
Also published as: CN110932628A; WO2021115049A1

Abstract

The application is applicable to the technical field of motors, and provides a five-phase motor pulse width modulation method, a device and terminal equipment, wherein the five-phase motor pulse width modulation method comprises the steps of obtaining a fundamental wave reference voltage vector and a third harmonic wave reference voltage vector; determining a preset number of fundamental wave vectors and a preset number of third harmonic wave vectors according to the positions of the fundamental wave reference voltage vectors in a fundamental wave voltage space vector diagram and the positions of the third harmonic wave reference voltage vectors in a third harmonic wave voltage space vector diagram; determining a fundamental wave modulation vector, a third harmonic modulation vector and modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector and each action time; and modulating the fundamental wave reference voltage vector and the third harmonic wave reference voltage vector based on the fundamental wave modulation vector, the third harmonic wave modulation vector and the modulation time. The problem that the five-phase motor cannot inject third harmonic voltage is solved.

Description

Pulse width modulation method and device for five-phase motor and terminal equipment

Technical Field

The application belongs to the technical field of motors, and particularly relates to a five-phase motor pulse width modulation method, a five-phase motor pulse width modulation device and terminal equipment.

Background

The permanent magnet synchronous motor has the advantages of high power density, high efficiency, high torque density and the like, and is widely applied to the fields of aerospace, industrial automation, electric automobiles and the like. Although the industry is still mainly three-phase permanent magnet synchronous motors, five-phase permanent magnet synchronous motors are becoming research hotspots due to their excellent performance. Because the included angle of two adjacent vectors in the vector pulse width modulation of the five-phase motor is 36 degrees, and the included angle of two adjacent vectors in the three-phase motor is 60 degrees, the five-phase permanent magnet synchronous motor has smaller torque fluctuation in the modulation process, and in addition, the five-phase permanent magnet synchronous motor also has larger energy density.

At present, a five-phase permanent magnet synchronous motor is controlled based on a traditional adjacent four-vector pulse width modulation algorithm, the traditional adjacent four-vector pulse width modulation algorithm cannot inject third harmonic voltage, so that the back electromotive force of the third harmonic is increased under the high-torque working condition of the motor due to the change of inductance, the harmonic characteristic of the motor current is poor, and the motor torque is influenced.

Disclosure of Invention

The embodiment of the application provides a pulse width modulation method and device for a five-phase motor and terminal equipment, and can solve the problem that the control of the five-phase motor cannot inject third harmonic voltage.

In a first aspect, an embodiment of the present application provides a five-phase motor pulse width modulation method, including:

acquiring a fundamental wave reference voltage vector and a third harmonic wave reference voltage vector;

determining a preset number of fundamental wave vectors and a preset number of third harmonic wave vectors according to the positions of the fundamental wave reference voltage vectors in a fundamental wave voltage space vector diagram and the positions of the third harmonic wave reference voltage vectors in a third harmonic wave voltage space vector diagram; wherein each fundamental wave vector corresponds to an action time;

determining a fundamental wave modulation vector, a third harmonic modulation vector and a modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector and each action time;

modulating the fundamental reference voltage vector and the third harmonic reference voltage vector based on the fundamental modulation vector, the third harmonic modulation vector, and the modulation time.

In one possible implementation manner of the first aspect, the determining a preset number of fundamental wave vectors and a preset number of third harmonic vectors according to a position of the fundamental wave reference voltage vector in a fundamental voltage space vector diagram and a position of the third harmonic reference voltage vector in a third harmonic voltage space vector diagram includes:

determining a first target sector in which the fundamental wave reference voltage vector is located in the fundamental wave voltage space vector diagram;

determining a second target sector where the third harmonic reference voltage vector is located in the third harmonic voltage space vector diagram according to the first target sector;

determining each fundamental wave vector according to the first target sector and the second target sector;

determining a corresponding third harmonic vector according to each fundamental vector; and each fundamental wave vector and each third harmonic wave vector are in a mapping relation.

In one possible implementation manner of the first aspect, the determining a fundamental wave modulation vector, a third harmonic modulation vector, and a modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector, and each action time includes:

establishing a first relation comprising the fundamental reference voltage vector, the third harmonic reference voltage vector, the fundamental vector, the third harmonic vector and each of the action times;

orthogonal decomposition is carried out on the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector and the third harmonic vector respectively to obtain decomposition parameters respectively corresponding to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector and the third harmonic vector, and a second relational expression is obtained according to each obtained decomposition parameter and the first relational expression;

reducing the dimension of each action time in the second relational expression to obtain a third relational expression;

and solving the third relation, and determining the fundamental wave modulation vector, the third harmonic modulation vector and the modulation time corresponding to each fundamental wave modulation vector.

In a possible implementation manner of the first aspect, the solving the third relation to determine the fundamental wave modulation vector, the third harmonic modulation vector, and the modulation time corresponding to each fundamental wave modulation vector includes:

determining a first solution result of the third relation under the condition that each action time is zero;

removing the solving result corresponding to the action time smaller than zero in the first solving result to obtain a second solving result;

selecting a solving result corresponding to the minimum switching frequency from the second solving results as modulation time;

determining the corresponding fundamental wave modulation vector according to the modulation time;

determining the third harmonic modulation vector based on the fundamental modulation vector.

In one possible implementation manner of the first aspect, the determining a fundamental wave modulation vector, a third harmonic modulation vector, and a modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector, and each action time further includes:

under the condition that the sum of the modulation times is larger than a preset time value, calculating the ratio of the modulation times to the total modulation time value; wherein, the total value of the modulation time is the sum of the modulation times;

and correcting each modulation time according to the product of each ratio and the preset time value.

In one possible implementation manner of the first aspect, the modulating the fundamental wave reference voltage vector and the third harmonic reference voltage vector based on the fundamental wave modulation vector, the third harmonic modulation vector, and the modulation time includes:

modulating the fundamental wave reference voltage vector according to the product of the fundamental wave modulation vector and the corresponding modulation time;

and modulating the third harmonic reference voltage vector according to the product of the third harmonic modulation vector and the corresponding modulation time.

In a possible implementation manner of the first aspect, the method further includes:

and under the condition that the modulated third harmonic voltage vector is larger than a preset vector value, taking the preset vector value as the modulated third harmonic voltage vector.

In a second aspect, an embodiment of the present application provides a five-phase motor pulse width modulation apparatus, including:

the reference vector acquisition module is used for acquiring a fundamental wave reference voltage vector and a third harmonic wave reference voltage vector;

the vector determining module is used for determining a preset number of fundamental wave vectors and a preset number of third harmonic wave vectors according to the position of the fundamental wave reference voltage vector in a fundamental wave voltage space vector diagram and the position of the third harmonic wave reference voltage vector in a third harmonic wave voltage space vector diagram; wherein each fundamental wave vector corresponds to an action time;

a modulation parameter determination module, configured to determine a fundamental wave modulation vector, a third harmonic modulation vector, and a modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector, and each action time;

a modulation module to modulate the fundamental reference voltage vector and the third harmonic reference voltage vector based on the fundamental modulation vector, the third harmonic modulation vector, and the modulation time.

In a third aspect, an embodiment of the present application provides a terminal device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor implements the method of any one of the above first aspects when executing the computer program.

In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the computer program implements the method of any one of the first aspect.

In a fifth aspect, the present application provides a computer program product, which when run on a terminal device, causes the terminal device to execute the method of any one of the above first aspects.

Compared with the prior art, the embodiment of the application has the advantages that:

according to the method and the device, a fundamental wave reference voltage vector and a third harmonic reference voltage vector are obtained, a preset number of fundamental wave vectors and a preset number of third harmonic vectors are determined according to the position of the fundamental wave reference voltage vector in a fundamental wave voltage space vector diagram and the position of the third harmonic reference voltage vector in the third harmonic voltage space vector diagram, and each fundamental wave vector corresponds to an action time; and then according to the fundamental wave reference voltage vector, the third harmonic wave reference voltage vector, the fundamental wave vector, the third harmonic wave vector and each action time, determining a fundamental wave modulation vector, a third harmonic wave modulation vector and a modulation time corresponding to each fundamental wave modulation vector, and modulating the fundamental wave reference voltage vector and the third harmonic wave reference voltage vector based on the fundamental wave modulation vector, the third harmonic wave modulation vector and the modulation time. By the method, the third harmonic and the fundamental wave are modulated, the modulated signal drives the five-phase motor, the injection of the third harmonic is realized, and the additional torque is added to the five-phase motor by utilizing the third harmonic current.

It is understood that the beneficial effects of the second aspect to the fifth aspect can be referred to the related description of the first aspect, and are not described herein again.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic diagram of a five-phase motor pulse width modulation system according to an embodiment of the present application;

fig. 2 is a schematic flowchart of a pulse width modulation method for a five-phase motor according to an embodiment of the present application;

fig. 3 is a schematic flowchart of a pulse width modulation method for a five-phase motor according to an embodiment of the present application;

fig. 4 is a fundamental voltage space vector diagram provided by an embodiment of the present application;

FIG. 5 is a third harmonic voltage space vector diagram provided by an embodiment of the present application;

fig. 6 is a schematic flowchart of a pulse width modulation method for a five-phase motor according to an embodiment of the present application;

FIG. 7 is a schematic diagram illustrating an orthogonal decomposition of a fundamental reference voltage vector according to an embodiment of the present application;

FIG. 8 is a schematic diagram illustrating an orthogonal decomposition of a third harmonic reference voltage vector according to an embodiment of the present application;

fig. 9 is a schematic flowchart of a pulse width modulation method for a five-phase motor according to an embodiment of the present application;

fig. 10 is a schematic flowchart of a pulse width modulation method for a five-phase motor according to an embodiment of the present application;

fig. 11 is a schematic flowchart of a pulse width modulation method for a five-phase motor according to an embodiment of the present application;

FIG. 12 is a schematic diagram of a simulation model provided in an embodiment of the present application;

FIG. 13 is a simulation diagram of a third harmonic-free reference voltage vector injection according to an embodiment of the present application;

FIG. 14 is a simulation diagram illustrating a third harmonic reference voltage vector injection according to an embodiment of the present application;

FIG. 15 is a waveform diagram of voltage counter electromotive force under no-load condition of the motor according to an embodiment of the present application;

FIG. 16 is a diagram illustrating harmonic amplitude analysis under no-load conditions of a motor according to an embodiment of the present disclosure;

FIG. 17 is a diagram illustrating harmonic phase analysis under no-load conditions of a motor according to an embodiment of the present disclosure;

FIG. 18 is a waveform of voltage counter electromotive force under the load condition of the motor according to an embodiment of the present application;

FIG. 19 is a graph illustrating harmonic amplitude analysis under a load condition of a motor according to an embodiment of the present disclosure;

FIG. 20 is a diagram illustrating harmonic phase analysis under a load condition of a motor according to an embodiment of the present disclosure;

FIG. 21 is a d-axis and q-axis vector position diagram of the fundamental and third harmonic of the motor according to an embodiment of the present application;

fig. 22 is a diagram illustrating simulation of an on/off state of a phase a switch of a motor after a third harmonic voltage vector is injected and modulated by a conventional four-vector converter according to an embodiment of the present disclosure;

FIG. 23 is a waveform diagram of an A-phase voltage of a motor after a third harmonic voltage vector is injected and modulated by a conventional four-vector converter according to an embodiment of the present disclosure;

fig. 24 is a waveform diagram of a phase voltage a of the motor after a third harmonic voltage vector is injected and modulated by a pulse width modulation method of the five-phase motor according to an embodiment of the present application;

fig. 25 is a simulation diagram of an on-off state of a phase a switch of a motor after a third harmonic voltage vector is injected and modulated by a five-phase motor pulse width modulation method according to an embodiment of the present application;

fig. 26 is a block diagram of a five-phase motor pulse width modulation apparatus according to an embodiment of the present application;

fig. 27 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to" determining "or" in response to detecting ". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".

Furthermore, in the description of the present application and the appended claims, the terms "first," "second," "third," and the like are used for distinguishing between descriptions and not necessarily for describing or implying relative importance.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

An application scenario of the pulse width modulation method of the five-phase motor in the present application is introduced first. Referring to fig. 1, a schematic diagram of a five-phase motor pulse width modulation system according to an embodiment of the present application is provided. As shown in fig. 1, the five-phase motor pulse width modulation system may include a signal input device 10, a signal modulation device 20, and a five-phase motor 30. The signal input device 10 may input the fundamental wave reference voltage vector and the third harmonic reference voltage vector to the signal modulation device 20. The signal modulation device 20 determines a preset number of fundamental wave vectors and a preset number of third harmonic wave vectors according to the position of the fundamental wave reference voltage vector in the fundamental wave voltage space vector diagram and the position of the third harmonic wave reference voltage vector in the third harmonic wave voltage space vector diagram; and finally, modulating the fundamental wave reference voltage vector and the third harmonic reference voltage vector based on the fundamental wave modulation vector, the third harmonic modulation vector and the modulation time. The signal modulation device 20 is used for realizing the common modulation of the fundamental wave reference voltage vector and the third harmonic wave reference voltage vector, so that the modulated fundamental wave reference voltage vector and the third harmonic wave reference voltage vector drive the five-phase motor 30 to rotate, the injection of the third harmonic wave is realized, and the third harmonic wave current is used for increasing the additional torque for the five-phase motor 30.

The technical solution in the embodiment of the present application is described below with reference to fig. 1.

Fig. 2 shows a schematic flow chart of a five-phase motor pulse width modulation method provided in an embodiment of the present application, and by way of example and not limitation, the above method may include the following steps:

s201, obtaining a fundamental wave reference voltage vector and a third harmonic wave reference voltage vector.

And S202, determining a preset number of fundamental wave vectors and a preset number of third harmonic wave vectors according to the position of the fundamental wave reference voltage vector in the fundamental wave voltage space vector diagram and the position of the third harmonic wave reference voltage vector in the third harmonic wave voltage space vector diagram.

In an embodiment, each fundamental wave vector corresponds to an action time, and referring to fig. 3, the step S202 may specifically include the following steps:

s2021, in the fundamental voltage space vector diagram, determines a first target sector in which the fundamental reference voltage vector is located.

In one embodiment, the direction of the five-phase winding (e.g., A, B, C, D, E direction in fig. 4) and its opposite direction in a five-phase motor may divide the fundamental voltage space into 10 regions, with each region being bounded by a boundary markerIs recorded as Q ^y1 … 10, each boundary having a large vector composed of different switch states

Middle vector

Sum small vector

On the basis of the 10 regions of the fundamental voltage space, each region is equally divided into two sectors, so that the fundamental voltage space is divided into 20 sectors, each sector is numbered and respectively marked with S^xAnd x is 1 … 20, the angle of each sector being 18 °. Based on the fundamental voltage space boundary Q^yThe left and right 18 degrees of the range of the resolution area D is divided into 10 solution areas D^yAnd y is 1 … 10, thus forming the space vector diagram of the fundamental voltage shown in fig. 4.

Illustratively, the fundamental reference voltage vector U is determined in the fundamental voltage space vector diagram shown in FIG. 4_aThe sector is taken as the first target sector.

S2022, according to the first target sector, determining a second target sector where the third harmonic reference voltage vector is located in the third harmonic voltage space vector diagram.

In one embodiment, the direction of the five-phase winding of a five-phase motor (e.g., A, B, C, D, E direction in fig. 5) and its opposite direction may divide the third harmonic voltage space into 10 regions based on the boundary Q in fig. 4^yThe boundary position corresponding to the third harmonic voltage space is marked as Q^y', y-1 … 10. Based on the large vectors in FIG. 4

Middle vector

Sum small vector

Projecting in the third harmonic voltage space to obtain corresponding large vector

Middle vector

Sum small vector

This forms the third harmonic voltage space vector diagram shown in fig. 5.

Illustratively, the fundamental reference voltage vector U is determined in step S2021_aThe first sector in which the voltage reference is located, and the fundamental wave reference voltage vector U_aThe nearest boundary is Q^y. Finding the boundary Q in the third harmonic voltage space vector diagram^yCorresponding boundary Q^y', then with a boundary Q^y' rotate 180 ° counterclockwise, the area formed is sector a; by the boundary Q^y'180 DEG clockwise rotation, forming the region of sector B, and then determining the third harmonic reference voltage vector U'_aThe sector in the third harmonic voltage space vector diagram serves as the second target sector.

S2023, determining each fundamental wave vector according to the first target sector and the second target sector.

It should be noted that the number of the fundamental wave vectors determined in step S2023 is at least five, different numbers of fundamental wave vectors are selected, the calculation methods are the same, and for convenience of description, the embodiment of the present application is described in the case of determining the number of the fundamental wave vectors to be five.

Illustratively, step S2021 determines the first target sector of the fundamental voltage reference voltage vector located in the fundamental voltage space vector diagram as S^2ySector, y 1 … 10, step S2022 determines a third harmonic reference voltage vector U'_aThe second target sector located in the third harmonic voltage space vector diagram is an a sector or a B sector. According to the first target sector and the second target sector, each fundamental wave vector is determined, and the corresponding relation is shown in table 1.

TABLE 1

Wherein S is^2y-A denotes that the first target sector is S^2yThe second target sector is an A sector; s^2y-B denotes that the first target sector is S^2yThe second target sector is a B sector; s^2y-1-A denotes that the first target sector is S^2y-1The second target sector is an A sector; s^2y-1-B denotes that the first target sector is S^2y-1And the second target sector is a B sector.

S2024, determining a corresponding third harmonic vector according to each fundamental vector.

And each fundamental wave vector and each third harmonic wave vector are in a mapping relation.

Illustratively, referring to fig. 4 and 5, when the first target sector is S^2yWhen the sector and the second target sector are A sectors, the determined fundamental wave vector comprises three large vectors

And two medium vectors

The action time corresponding to the three large vectors and the two medium vectors is respectively

After the fundamental wave vector is confirmed, mapping each vector in a third harmonic voltage space vector diagram to obtain third harmonic vectors which are respectively

Wherein

In the form of a small vector, the vector,

is a medium vector (as shown in FIG. 5)) The action time of each third harmonic vector is respectively

And S203, determining a fundamental wave modulation vector, a third harmonic modulation vector and modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector and each action time.

In an embodiment, referring to fig. 6, step S203 may specifically include the following steps:

s2031, establishing a first relational expression containing a fundamental wave reference voltage vector, a third harmonic wave reference voltage vector, a fundamental wave vector, a third harmonic wave vector and each action time.

Illustratively, the fundamental reference voltage vector is U_aThe third harmonic reference voltage vector is U'_aThe fundamental wave vectors are respectively

The third harmonic vectors are respectively

The action time of each vector is

Establishing a first relation based on the above parameters:

wherein the content of the first and second substances,

U_dcis the DC bus voltage of the inverter, T_sIs a modulation period of PWM.

S2032, orthogonal decomposition is carried out on the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector and the third harmonic vector respectively to obtain decomposition parameters respectively corresponding to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector and the third harmonic vector, and a second relational expression is obtained according to the obtained decomposition parameters and the first relational expression.

Illustratively, the fundamental reference voltage vector is U_aThe nearest boundary in the space vector diagram of the fundamental voltage is Q^yFundamental reference voltage vector is U_aAnd the boundary Q^yThe included angle between is theta₁，-1/10π<θ ₁1/10 pi or less and third harmonic reference voltage vector U'_aAnd the boundary Q^yThe angle of' is theta₃At the boundary Q^yAnd boundary Q^yThe vertical line of the reference voltage vector is set up as a coordinate system, and the vector of the reference voltage of the fundamental wave is U_aOrthogonal decomposition to obtain U_αAnd U_β(as shown in FIG. 7); by the boundary Q^yAnd boundary Q^yEstablishing a coordinate system for the vertical lines, and carrying out orthogonal decomposition on each fundamental wave vector to obtain corresponding decomposition parameters; by the boundary Q^y' and boundary Q^y'the vertical line establishes a coordinate system for the third harmonic reference voltage vector U'_aOrthogonal decomposition to give U'_αAnd U'_β(as shown in FIG. 8); by the boundary Q^y' and boundary Q^yThe vertical line of' establishes a coordinate system, and carries out orthogonal decomposition on each third harmonic vector to obtain a corresponding decomposition parameter.

Substituting the obtained decomposition parameters into the first relational expression to obtain a second relational expression as follows:

wherein the content of the first and second substances,

the second relationship can also be simplified as:

s2033, reducing the dimension of each action time in the second relational expression to obtain a third relational expression.

For example, the second relation obtained in step S2032 includes four equations and five unknowns, so that the solution of the equations cannot be obtained, and the switching-off times of the inverter switches may be increased because the principle of central symmetry cannot be satisfied by modulating five voltage vectors simultaneously in the five-phase inverter. Therefore, it is necessary to obtain an analytical expression of the action time T by using four unknowns as the five unknowns in the second relational expression for the above two reasons.

Reducing the dimension of each action time in the second relational expression to obtain a third relational expression:

T′＝A*V_a/U_dc

wherein T' is a 4 x 1 dimensional matrix after dimension reduction of T,

a is a 4 x 4 dimensional full rank matrix,

and S2034, solving the third relation, and determining the fundamental wave modulation vector, the third harmonic wave modulation vector and the modulation time corresponding to each fundamental wave modulation vector.

In one embodiment, referring to fig. 9, step S2034 may specifically include the following steps:

s20341, under the condition that each action time is zero, determines the first solution result of the third relation.

Exemplary, order

Respectively equals to zero, and different analytic solutions of A are obtained and respectively set as A₁、A₂、A₃、A₄And A₅Wherein:

if it is

Is equal to zero, A₄Without solution, A₁、A₂、A₃And A₅Is the first solution result of the third relation.

S20342, removing the solving result corresponding to the action time smaller than zero in the first solving result to obtain a second solving result.

Exemplary, because

For the action time of the respective fundamental wave vector, and

not less than zero. If the action time is less than zero in the solution obtained in step S20341, the obtained solution is not correct, and therefore the incorrect solution is eliminated.

S20343, the solution result corresponding to the minimum switching frequency is selected as the modulation time from the second solution results.

For example, after removing the incorrect solution in step S20342, the remaining solution is the second solution result, and then the solution result corresponding to the minimum switching frequency is selected from the second solution result, so that a solution with a unique action time can be obtained as the modulation time.

S20344, a corresponding fundamental wave modulation vector is determined according to the modulation time.

For example, since each fundamental wave vector corresponds to an action time, if the modulation time obtained in step S20343 is equal to

Then the corresponding can be determined in the fundamental vector

As a fundamental modulation vector.

S20345, a third harmonic modulation vector is determined based on the fundamental modulation vector.

Illustratively, since the fundamental wave vector and the third harmonic wave vector are in a mapping relationship, the third harmonic wave modulation vector is determined according to the fundamental wave modulation vector obtained in step S20344. E.g. fundamental modulation vector of

Third harmonic modulation vector

In an embodiment, referring to fig. 10, step S203 may further include the following steps:

s20301, calculating the ratio of each modulation time to the total modulation time when the sum of the modulation times is larger than the preset time value.

S20302, correcting each modulation time according to the product of each ratio and the preset time value.

For example, the total modulation time may be set to one PWM period T_sIn order to prevent the overmodulation phenomenon, the sum of the action times of the vectors should be less than T_s. When the total value of all the modulation times is greater than the preset time value T_sThen, the modulation time is revised as follows:

i.e. if the sum of the modulation times T'₁₁+T′₂₁+T′₃₁+T′₄₁>T_sAnd then, distributing the time of each modulation time according to the formula to obtain the final modulation time.

And S204, modulating the fundamental wave reference voltage vector and the third harmonic reference voltage vector based on the fundamental wave modulation vector, the third harmonic modulation vector and the modulation time.

In an embodiment, referring to fig. 11, step S204 may further include the following steps:

s2041, the fundamental reference voltage vector is modulated according to the product of the fundamental modulation vector and the corresponding modulation time.

And S2042, modulating the third harmonic reference voltage vector according to the product of the third harmonic modulation vector and the corresponding modulation time.

Specifically, the fundamental wave reference voltage vector is modulated by step S2041, the third harmonic reference voltage vector is modulated by step S2042, and the modulated fundamental wave reference voltage vector and the third harmonic reference voltage vector simultaneously drive the five-phase motor.

In one embodiment, the preset vector value is taken as the modulated third harmonic voltage vector in case the modulated third harmonic voltage vector is larger than the preset vector value.

Specifically, if the modulated third harmonic voltage vector is too large, T' in the calculated modulation time may be a negative number, and since the torque in the five-phase motor is mainly provided by the fundamental wave torque, in order to ensure the normal operation of the motor, the fundamental wave reference voltage vector U is preferentially ensured_aIn the case of normal modulation, since the third harmonic reference voltage is modulated as much as possible, it is necessary to provide the third harmonic reference voltage vector U'_aA restriction is made. First, let third harmonic reference voltage vector U'_aMaximum value of U 'capable of being modulated'_max(Preset vector value), mixing T'₁₁，T′₂₁，T′₃₁，T′₄₁Substituting more than or equal to 0 into the third relation to obtain:

the formula is simplified to obtain:

wherein:

for third harmonic reference voltage vector U'_aThe limitations are made as follows:

if U is_a/U′_max>max(τ₁,τ₂,τ₃,τ₄) Then, then

The traditional four-vector pulse width modulation algorithm is modulated by two adjacent large vectors and two middle vectors, and because the amplitude of the middle vector is 1.618 times of that of the large vectors in the third harmonic space, the third harmonic voltage vector of the motor can be counteracted by ensuring that the action time of the large vectors is 1.618 times of that of the middle vectors. However, a small amount of third harmonic flux linkage exists in the body of the five-phase motor, and when the five-phase motor operates under the rated working condition of the motor, third harmonic voltage vectors are generated due to the phenomenon of inductance saturation. The traditional four-vector pulse width modulation algorithm cannot modulate the third harmonic voltage vector, so that the good harmonic characteristic of the five-phase motor is difficult to ensure when the motor runs under high load.

The pulse width modulation method of the five-phase motor can modulate a third harmonic voltage vector, and can ensure good harmonic characteristics when the motor runs under high load; and the injection of the third harmonic voltage vector into the five-phase motor under the rated working condition can increase the modulation ratio of the fundamental voltage vector, and can effectively improve the power density of the five-phase motor.

How to increase the modulation ratio of the bus voltage while increasing the third harmonic voltage vector in the five-phase motor pulse width modulation method is analyzed below, and the solution of A in the third relational expression is equal to A₃For example, let T_k＝T′₁₁+T′₂₁+T′₃₁+T′₄₁，T_kThe expression of (a) is as follows:

T_k＝(1.80903 U_a cos(θ₁)+0.5878 U_a sin(θ₁)

+0.6910 U′_a cos(θ₃)+0.9517 U′_a sin(θ₃))/U_dc*T_s

if there is no third harmonic voltage vector U'_aAt the time of injection, T is_kSimplifying to obtain:

wherein theta is more than or equal to 18 degrees below zero₁≤18°。

Reissue of order T_k≤T_sThe formula is simplified to obtain:

U_a≤U_dc/(1.80903cos(θ₁)+0.5878sin(θ₁))

it can be obtained that when there is no third harmonic voltage vector injection, the modulation ratio of the bus voltage of the algorithm is 0.526, which is equal to the conventional four-vector pulse width modulation ratio.

If there is third harmonic voltage vector injection, T is calculated by trigonometric function auxiliary angle formula_kThe expression of (c) is transformed to yield:

T_k＝(1.80903U_a cos(θ₁)+0.5878U_a sin(θ₁)

+1.1761U′_a cos(θ₃-3/10π))/U_dc*T_s

when 4/5 pi is less than or equal to theta₃When the pi is less than or equal to 9/5, cos (theta)₃-3/10π)<0, adding a third harmonic reference voltage vector U'_aThen T is_kIt will be reduced, i.e. after injecting the third harmonic voltage vector, less modulation time will be required to modulate the fundamental voltage vector of the same size, which means that in equal modulation time, a larger fundamental voltage vector can be modulated, thereby increasing the modulation ratio of the fundamental bus voltage. If the solution of A in the third relation is other values (i.e. A is A)₁、A₂Or A₅) Similarly, theta can be obtained₃Within a certain angle range, adding a third harmonic voltage vector U'_aThe bus voltage modulation ratio of the fundamental wave can be increased.

In order to verify the effectiveness and the correctness of the five-phase motor pulse width modulation method for the bus voltage modulation strategy, a simulation model is built by using Simulink (as shown in FIG. 12), and the model is verified.

The reference voltage input device inputs reference voltage vectors (including a fundamental voltage reference vector and a third harmonic reference voltage vector), the signal processor modulates the output reference voltage vectors and then outputs modulated signals to control the motor.

When the input fundamental wave voltage reference vector is 52.7V and the third harmonic reference voltage vector is 0V, a voltage waveform diagram of the a phase of the five-phase motor is obtained (as shown in fig. 13). As can be seen from the waveform diagram of the a-phase voltage in fig. 13, when there is no third harmonic reference voltage vector injection, the modulation ratio of the five-phase motor pulse width modulation method to the bus voltage through the embodiment of the present application is equal to the modulation ratio of the conventional four-vector pulse width modulation method to the bus voltage. Because the bus voltage of the simulation motor is 100V, the maximum voltage which can be modulated is 52.6V when no third harmonic reference voltage vector is injected.

When the phase difference between the fundamental voltage reference vector and the third harmonic voltage reference vector

And meanwhile, the third harmonic reference voltage vector is injected to maximize the modulation ratio of the bus voltage. Then, thePhase difference taking

Fundamental voltage reference vector U₃14.2V, third harmonic reference voltage vector U₁60.4V, bus voltage U_dcThe voltage waveform diagram of the phase a of the five-phase motor was simulated (as shown in fig. 14) at 100V, and it was seen from the voltage waveform diagram of the phase a in fig. 14 that the bus voltage modulation ratio reached 0.604, which is higher than that when the third harmonic reference voltage vector was not injected.

In the low-torque and low-power operation of the motor, the smoothness of the operation of the motor can be met, but in the high-torque and high-rotation speed of the motor, the bus voltage duty ratio of the motor can greatly influence the modulation ratio of the bus voltage. In addition, under the high torque condition of the motor, because the inductance of the direct axis and the quadrature axis of the motor changes, the amplitude of the back electromotive force third harmonic of the five-phase motor is increased, and the back electromotive force third harmonic of the five-phase motor has a phase lag phenomenon compared with that in a no-load state. Based on the phenomenon, if the third harmonic voltage can not be modulated to resist the third harmonic counter electromotive force, the motor can generate the third harmonic current which is not beneficial to the torque promotion of the motor and the efficiency reduction of the motor, and the smoothness reduction of the motor under the high-torque working condition is caused. The lower graph is a finite element analysis of the back electromotive force characteristics of the five-phase Motor under no-load working conditions and load working conditions by using a Motor-CAD.

As can be seen from fig. 15 to 20, as the motor torque increases, the third harmonic characteristic will also change, and in the motor no-load torque, the motor back electromotive force phase is as follows (since the fundamental back electromotive force direction of the rotor is located on the fundamental q axis, a coordinate system is established below with the fundamental q axis as the starting position and the counterclockwise rotation direction as the positive direction):

V＝A₁*sin(x-18°)+A₃*sin(3x-55°)

let y equal to x +18 ° to obtain

V＝A₁*sin(y)+A₃*sin(3y+1°)

From the above expression, it can be seen that the motor third harmonic flux linkage is almost in the same phase as the fundamental flux linkage, as shown in fig. 21.

Then, under the rated working condition of the motor, 7.11A/mm is introduced²And (3) analyzing the back electromotive force characteristic of the finite element model of the five-phase motor to obtain a relational expression:

V＝A₁*sin(x-339.7°)+A₃*sin(3x-114.6°)

let y be x +20.3 °, yield:

V＝A₁*sin(y)+A₃*sin(y+184.5°)

by comparing finite element analysis under no-load and rated working conditions, the fact that when the motor current is increased, the third harmonic counter electromotive force amplitude of the motor is increased, the third harmonic counter electromotive force phase lags behind the counter electromotive force of the fundamental wave by about 184.5 degrees compared with the no-load state can be obtained.

Next, a third harmonic voltage with an amplitude of 13.8V and a phase lag of 184.5 ° is injected on the basis of a fundamental voltage amplitude of 59V, the model is simulated by using Simulink, and the third harmonic voltage is modulated by using a conventional four-vector modulation method and a five-phase motor pulse width modulation method in the embodiment of the present application, so as to obtain corresponding simulation diagrams, as shown in fig. 22 to 25.

As can be seen from fig. 22 to fig. 25, after the third harmonic voltage vector lagging the phase angle of 184.5 ° is injected, the motor a-phase switch after the conventional four-vector modulation algorithm can still be normally turned on and off, while the five-phase motor pulse width modulation algorithm provided by the embodiment of the present application reaches saturation under the condition that the modulation amplitude is 52.6V voltage (the maximum bus voltage modulation ratio of the algorithm is 0.526). Therefore, the simulation verifies that the injection of the third harmonic wave promotes the improvement of the modulation ratio of the fundamental voltage under the rated operation condition of the five-phase motor.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Fig. 26 shows a structural block diagram of a five-phase motor pulse width modulation device provided in the embodiment of the present application, corresponding to the five-phase motor pulse width modulation method in the foregoing embodiment, and only shows portions related to the embodiment of the present application for convenience of description.

Referring to fig. 26, the five-phase motor pulse width modulation apparatus in the embodiment of the present application may include a reference vector acquisition module 261, a vector determination module 262, a modulation parameter determination module 263, and a modulation module 264.

The reference vector acquiring module 261 is configured to acquire a fundamental reference voltage vector and a third harmonic reference voltage vector;

a vector determination module 262, configured to determine a preset number of fundamental wave vectors and a preset number of third harmonic vectors according to a position of the fundamental wave reference voltage vector in a fundamental voltage space vector diagram and a position of the third harmonic reference voltage vector in a third harmonic voltage space vector diagram; wherein each fundamental wave vector corresponds to an action time;

a modulation parameter determining module 263, configured to determine a fundamental wave modulation vector, a third harmonic modulation vector, and a modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector, and each action time;

a modulation module 264 for modulating the fundamental reference voltage vector and the third harmonic reference voltage vector based on the fundamental modulation vector, the third harmonic modulation vector, and the modulation time.

In one embodiment, the vector determination module 262 may include a first target sector determination module, a second target sector determination module, a fundamental vector determination module, and a third harmonic vector determination module.

The first target sector determining module is configured to determine, in the fundamental voltage space vector diagram, a first target sector in which the fundamental reference voltage vector is located;

a second target sector determining module, configured to determine, according to the first target sector, a second target sector in which the third harmonic reference voltage vector is located in the third harmonic voltage space vector diagram;

a fundamental wave vector determining module, configured to determine each fundamental wave vector according to the first target sector and the second target sector;

the third harmonic vector determining module is used for determining corresponding third harmonic vectors according to the fundamental wave vectors; and each fundamental wave vector and each third harmonic wave vector are in a mapping relation.

In one embodiment, the modulation parameter determination module 263 may further include a first relation determination module, a second relation determination module, a third relation determination module, and a modulation data determination module.

The first relation determining module is used for establishing a first relation containing the fundamental wave reference voltage vector, the third harmonic wave reference voltage vector, the fundamental wave vector, the third harmonic wave vector and each action time;

a second relational expression determining module, configured to perform orthogonal decomposition on the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, and the third harmonic vector, respectively, to obtain decomposition parameters corresponding to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, and the third harmonic vector, respectively, and obtain a second relational expression according to the obtained decomposition parameters and the first relational expression;

a third relation determining module, configured to perform dimension reduction on each action time in the second relation to obtain a third relation;

and the modulation data determining module is used for solving the third relation and determining the fundamental wave modulation vector, the third harmonic modulation vector and the modulation time corresponding to each fundamental wave modulation vector.

In one embodiment, the modulation data determination module may include a first solving module, a second solving module, a modulation time determination module, a fundamental modulation vector determination module, and a third harmonic modulation vector determination module.

The first solving module is used for determining a first solving result of the third relation under the condition that each action time is zero;

the second solving module is used for removing the solving result corresponding to the action time smaller than zero in the first solving result to obtain a second solving result;

a modulation time determining module, configured to select a solution result corresponding to the minimum switching frequency from the second solution result as a modulation time;

the fundamental wave modulation vector determining module is used for determining the corresponding fundamental wave modulation vector according to the modulation time;

a third harmonic modulation vector determination module to determine the third harmonic modulation vector based on the fundamental modulation vector.

In one embodiment, the modulation parameter determination module 263 may further include a comparison calculation module and a modification module.

The comparison calculation module is used for calculating the ratio of each modulation time to the total modulation time value under the condition that the sum of each modulation time is greater than a preset time value; wherein, the total value of the modulation time is the sum of the modulation times;

and the correction module is used for correcting each modulation time according to the product of each ratio and the preset time value.

In one embodiment, the modulation module 264 may include a fundamental reference voltage vector modulation module and a third harmonic reference voltage vector modulation module.

The fundamental wave reference voltage vector modulation module is used for modulating the fundamental wave reference voltage vector according to the product of the fundamental wave modulation vector and the corresponding modulation time;

and the third harmonic reference voltage vector modulation module is used for modulating the third harmonic reference voltage vector according to the product of the third harmonic modulation vector and the corresponding modulation time.

In one embodiment, the five-phase motor pulse width modulation device may further include a third harmonic voltage vector limitation module.

The third harmonic voltage vector limiting module is used for taking the preset vector value as the modulated third harmonic voltage vector under the condition that the modulated third harmonic voltage vector is larger than the preset vector value.

It should be noted that, for the information interaction, execution process, and other contents between the above-mentioned devices/units, the specific functions and technical effects thereof are based on the same concept as those of the embodiment of the method of the present application, and specific reference may be made to the part of the embodiment of the method, which is not described herein again.

The five-phase motor pulse width modulation device shown in fig. 26 may be a software unit, a hardware unit, or a combination of software and hardware unit built in an existing terminal device, may be integrated into the terminal device as an independent pendant, or may exist as an independent terminal device.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

Fig. 27 is a schematic structural diagram of a terminal device according to an embodiment of the present application. As shown in fig. 27, the terminal device 27 of this embodiment may include: at least one processor 272 (only one processor 272 is shown in fig. 27), a memory 271, and a computer program 273 stored in the memory 271 and operable on the at least one processor 272, wherein the processor 272 implements the steps in any of the above-described embodiments of the five-phase motor pulse width modulation method, such as the steps S201 to S204 in the embodiment shown in fig. 2, when executing the computer program 273. Alternatively, the processor 51 implements the functions of the modules/units in the respective five-phase motor pulse width modulation device embodiments described above, such as the functions of the modules 261 to 264 shown in fig. 26, when executing the computer program 273.

Illustratively, the computer program 273 may be divided into one or more modules/units, which are stored in the memory 271 and executed by the processor 272 to implement the present invention. The one or more modules/units may be a series of computer program 273 instruction segments capable of performing specific functions, which are used to describe the execution process of the computer program 273 in the terminal device 27.

The terminal device 27 may be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The terminal device 27 may include, but is not limited to, a processor 272 and a memory 271. Those skilled in the art will appreciate that fig. 27 is merely an example of the terminal device 27, and does not constitute a limitation to the terminal device 27, and may include more or less components than those shown, or combine some components, or different components, such as an input/output device, a network access device, and the like.

The Processor 272 may be a Central Processing Unit (CPU), and the Processor 272 may be other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The storage 271 may be an internal storage unit of the terminal device 27 in some embodiments, for example, a hard disk or a memory of the terminal device 27. The memory 271 may also be an external storage device of the terminal device 27 in other embodiments, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like provided on the terminal device 27. Further, the memory 271 may include both an internal storage unit and an external storage device of the terminal device 27. The memory 271 is used for storing an operating system, an application program, a BootLoader (BootLoader), data, and other programs, such as program codes of the computer program 273. The memory 271 may also be used to temporarily store data that has been output or is to be output.

Embodiments of the present application further provide a computer-readable storage medium, where the computer-readable storage medium stores a computer program 273, and the computer program 273 is implemented to implement the steps in the above-described method embodiments when executed by the processor 272.

The embodiments of the present application provide a computer program product, which when running on a mobile terminal, enables the mobile terminal to implement the steps in the above method embodiments when executed.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. With this understanding, all or part of the processes in the methods of the embodiments described above can be implemented by the computer program 273 instructing the relevant hardware, the computer program 273 can be stored in a computer-readable storage medium, and the computer program 273 can implement the steps of the methods described above when being executed by the processor 272. The computer program 273 includes computer program code, which may be in source code form, object code form, an executable file or some intermediate form, and so on. The computer readable medium may include at least: any entity or device capable of carrying computer program code to a photographing apparatus/terminal apparatus, a recording medium, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), an electrical carrier signal, a telecommunications signal, and a software distribution medium. Such as a usb-disk, a removable hard disk, a magnetic or optical disk, etc. In certain jurisdictions, computer-readable media may not be an electrical carrier signal or a telecommunications signal in accordance with legislative and patent practice.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus/network device and method may be implemented in other ways. For example, the above-described apparatus/network device embodiments are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implementing, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. A pulse width modulation method for a five-phase motor, comprising:

determining a fundamental wave modulation vector, a third harmonic modulation vector and modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector and each action time;

modulating the fundamental reference voltage vector and the third harmonic reference voltage vector based on the fundamental modulation vector, the third harmonic modulation vector, and the modulation time;

the determining a fundamental wave modulation vector, a third harmonic modulation vector and a modulation time corresponding to each fundamental wave modulation vector according to the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector and each action time comprises:

2. The five-phase motor pulse width modulation method according to claim 1, wherein the determining a predetermined number of fundamental wave vectors and a predetermined number of third harmonic vectors based on the position of the fundamental wave reference voltage vector in a fundamental voltage space vector diagram and the position of the third harmonic reference voltage vector in a third harmonic voltage space vector diagram comprises:

3. The five-phase motor pulse width modulation method according to claim 1, wherein the solving the third relation to determine the fundamental wave modulation vector, the third harmonic modulation vector, and the modulation time corresponding to each fundamental wave modulation vector comprises:

4. The five-phase motor pulse width modulation method according to claim 1 or 3, wherein the determining of a fundamental wave modulation vector, a third harmonic modulation vector, and a modulation time corresponding to each of the fundamental wave modulation vectors from the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector, and each of the action times, further comprises:

5. The five-phase electric machine pulse width modulation method of claim 1, wherein the modulating the fundamental reference voltage vector and the third harmonic reference voltage vector based on the fundamental modulation vector, the third harmonic modulation vector, and the modulation time comprises:

6. The five-phase electric machine pulse width modulation method of claim 1, further comprising:

7. A five-phase motor pulse width modulation apparatus, comprising:

a modulation module to modulate the fundamental reference voltage vector and the third harmonic reference voltage vector based on the fundamental modulation vector, the third harmonic modulation vector, and the modulation time;

the modulation parameter determining module comprises a first relation determining module, a second relation determining module, a third relation determining module and a modulation data determining module;

a first relation determining module for establishing a first relation including the fundamental wave reference voltage vector, the third harmonic reference voltage vector, the fundamental wave vector, the third harmonic vector and each of the action times;

8. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the method according to any of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the method according to any one of claims 1 to 6.