阅读说明：本技术 抑制车辆低速抖动的谐波电流注入方法、装置和计算机可读存储介质 (Harmonic current injection method, apparatus and computer-readable storage medium for suppressing vehicle low-speed jitter ) 是由 刘迪 王凯 于 2021-09-29 设计创作，主要内容包括：本发明公开了一种抑制车辆低速抖动的谐波电流注入方法、装置和计算机可读存储介质,提出极端低速工况下谐波电流与谐波转矩的关系式,进而依据该方程计算出抑制车辆低速抖动所需的5次、7次谐波电流给定值,然后将5次、7次谐波电流给定值变换至基波坐标系下,并一起叠加到作为基波电流环的基波电流给定值上,叠加之和作为电流环的输入量。本发明的谐波电流注入方法在抑制车辆极低速抖动的场景下达到非常好的效果。(The invention discloses a harmonic current injection method, a harmonic current injection device and a computer readable storage medium for inhibiting vehicle low-speed jitter, wherein a relational expression of harmonic current and harmonic torque under an extreme low-speed working condition is provided, then 5-order and 7-order harmonic current set values required for inhibiting the vehicle low-speed jitter are calculated according to the equation, then the 5-order and 7-order harmonic current set values are converted to a fundamental wave coordinate system and are superposed to a fundamental wave current set value serving as a fundamental wave current loop, and the superposed sum is used as the input quantity of the current loop. The harmonic current injection method of the invention achieves a good effect in the scene of inhibiting the vehicle from shaking at an extremely low speed.)

1. A harmonic current injection method for suppressing vehicle low-speed jitter is characterized by comprising the following steps:

(1) carrying out coordinate transformation on the three-phase sampling current to obtain d-axis and q-axis components of the total sampling current;

(2) calculating to obtain d-axis and q-axis component given values of 5-order and 7-order harmonic currents and d-axis and q-axis component given values of fundamental current according to harmonic torque and rotating speed of the permanent magnet synchronous motor;

(3) performing inverse Park transformation on the d-axis and q-axis component given values of the 5 th harmonic current and the 7 th harmonic current obtained in the step (2) to obtain the d-axis and q-axis component given values of the 5 th harmonic current and the 7 th harmonic current in a fundamental wave synchronous rotating coordinate system;

(4) superposing a d-axis component given value of 5-order harmonic current and a d-axis component given value of 7-order harmonic current on a d-axis component given value of fundamental current under a fundamental synchronous rotating coordinate system to obtain a d-axis component given value of a current loop; superposing a q-axis component given value of 5-order harmonic current and a q-axis component given value of 7-order harmonic current on a q-axis component given value of current loop fundamental current under a fundamental wave synchronous rotating coordinate system to obtain a d-axis component given value of a current loop; and then, respectively taking the d-axis component given value and the q-axis component given value of the current loop as input quantities of the d-axis current loop and the q-axis current loop to carry out closed-loop control on the d-axis component and the q-axis component corresponding to the sampling current, and finally respectively outputting voltage control signals of the d-axis current loop and the q-axis current loop.

2. The harmonic current injection method for suppressing the low speed jitter of the vehicle according to claim 1, wherein the calculation in step (2) obtains given values of d-axis and q-axis components of 5 th and 7 th harmonic currents by:

in the formula, T₆Representing 6 order torque, I_miRepresenting the i-order harmonic current amplitude, E_mjRepresenting the counter potential amplitude of the j order harmonic; t is_eRepresenting electromagnetic torque, omega representing electrical angular velocity of the motor, and omega representing mechanical angular velocity of the motor; theta denotes the initial phase of the fundamental wave, n_pRepresenting the number of pole pairs, L, of the motor_dRepresenting the direct-axis inductance, L_qRepresenting quadrature axis inductance;

and T₆Expressed as:

wherein the content of the first and second substances,

i_d1＝I_m1sinθ

i_q1＝I_m1cosθ

i_d5＝I_m5sin(6ωt+5θ+θ₅)

i_q5＝I_m5cos(6ωt+5θ+θ₅)

in the formula [ theta ]₅Representing the initial phase of the current of the 5 th harmonic;

on the premise that the given values of the d-axis component and the q-axis component of the 7 th harmonic current are set to be 0, the given values of the d-axis component and the q-axis component of the 5 th harmonic current are solved and serve as the given values of the d-axis component and the q-axis component of the 5 th harmonic current and the 7 th harmonic current.

3. The harmonic current injection method for suppressing the vehicle low-speed jitter according to claim 1, wherein the d-axis and q-axis components of the total sampled current obtained by performing the coordinate transformation on the three-phase sampled current in the step (1) are obtained by sampling U, V, W three-phase currents of the permanent magnet synchronous motor, and performing Clark transformation and Park transformation on the three-phase currents to obtain a two-phase synchronous rotating coordinate system, so that the d-axis and q-axis components of the total sampled current containing the harmonic current are obtained.

4. The harmonic current injection method for suppressing vehicle low-speed judder according to claim 1, characterized in that: and (4) performing closed-loop control on the d-axis component and the q-axis component corresponding to the sampling current by respectively using the d-axis component given value and the q-axis component given value of the current loop as input quantities of the d-axis current loop and the q-axis current loop, and controlling by adopting a proportional-integral regulator.

5. A computer-readable storage medium, wherein a harmonic current injection control program for suppressing vehicle low-speed judder is stored on the computer-readable storage medium, and the harmonic current injection control program executes the steps in the harmonic current injection method for suppressing vehicle low-speed judder according to any one of claims 1 to 4.

6. The permanent magnet synchronous motor control device is characterized by comprising a signal acquisition module, a memory, a processor, a controller and a harmonic current injection control program, wherein the signal acquisition module is used for sampling motor state signals and sending the signals to the processor, the processor runs the harmonic current injection control program to output voltage control signals and send the signals to the controller for controlling the voltage of a permanent magnet synchronous motor, and the harmonic current injection control program executes the steps in the harmonic current injection method for inhibiting the low-speed jitter of a vehicle according to any one of claims 1 to 4.

Technical Field

The present invention relates to a method for suppressing vehicle low-speed judder, and more particularly, to a method, an apparatus and a computer-readable storage medium for injecting harmonic current for suppressing vehicle low-speed judder.

Background

The harmonic component of the back electromotive force is inevitably generated in the design of the body of the permanent magnet synchronous motor, harmonic current is generated in a stator winding of the motor, high-order torque pulsation on a motor shaft can be caused under the interaction of the harmonic component of the back electromotive force, the harmonic current, the fundamental component of the back electromotive force and the fundamental current, and the problem of low-speed jitter of the vehicle is reflected under the working condition that the vehicle runs at low speed. In order to reduce the uncomfortable feeling of the user caused by the low-speed shaking of the vehicle, a software control method is adopted to reduce the high-order torque ripple by adopting a harmonic current injection method so as to inhibit the shaking situation under the low-speed working condition. However, the conventional harmonic current injection method is limited by the reason that the low-speed jitter frequency is in the bandwidth control range of the fundamental current loop, and the vehicle jitter condition under the speed working condition cannot be effectively inhibited.

Disclosure of Invention

The purpose of the invention is as follows: in view of the above problems, the present invention provides a harmonic current injection method, apparatus and computer readable storage medium for suppressing vehicle low speed jitter, which can effectively improve the vehicle low speed jitter problem.

The technical scheme is as follows: the technical scheme adopted by the invention is a harmonic current injection method for inhibiting low-speed vehicle jitter, which comprises the following steps of:

(1) carrying out coordinate transformation on the three-phase sampling current to obtain d-axis and q-axis components of the total sampling current; the method comprises the following steps: u, V, W three-phase current of the permanent magnet synchronous motor is sampled, and then subjected to Clark conversion and Park conversion to a two-phase synchronous rotating coordinate system to obtain d-axis and q-axis components of total sampling current containing harmonic current.

(2) Calculating to obtain d-axis and q-axis component given values of 5-order and 7-order harmonic currents and d-axis and q-axis component given values of fundamental current according to harmonic torque and rotating speed of the permanent magnet synchronous motor; the calculation formula is as follows:

in the formula, T₆Representing 6 order torque, I_miRepresenting the i-order harmonic current amplitude, E_mjRepresenting the counter potential amplitude of the j order harmonic; t is_eRepresenting electromagnetic torque, omega representing electrical angular velocity of the motor, and omega representing mechanical angular velocity of the motor; theta denotes the initial phase of the fundamental wave, n_pRepresenting the number of pole pairs, L, of the motor_dRepresenting the direct-axis inductance, L_qIndicating quadrature electricityFeeling;

and T₆Expressed as:

wherein the content of the first and second substances,

i_d1＝I_m1 sinθ

i_q1＝I_m1 cosθ

i_d5＝I_m5 sin(6ωt+5θ+θ₅)

i_q5＝I_m5 cos(6ωt+5θ+θ₅)

in the formula [ theta ]₅Representing the initial phase of the current of the 5 th harmonic;

on the premise that the given values of the d-axis component and the q-axis component of the 7 th harmonic current are set to be 0, the given values of the d-axis component and the q-axis component of the 5 th harmonic current are solved and serve as the given values of the d-axis component and the q-axis component of the 5 th harmonic current and the 7 th harmonic current.

(3) Performing inverse Park transformation on the d-axis and q-axis component given values of the 5 th harmonic current and the 7 th harmonic current obtained in the step (2) to obtain the d-axis and q-axis component given values of the 5 th harmonic current and the 7 th harmonic current in a fundamental wave synchronous rotating coordinate system;

(4) superposing the d-axis component given value of the 5 th harmonic current and the d-axis component given value of the 7 th harmonic current on the d-axis component given value of the current loop fundamental current under the fundamental wave synchronous rotating coordinate system to obtain a d-axis component given value i of the current loop_{d_ref}(ii) a Superposing a given value of a q-axis component of 5-order harmonic current and a given value of a q-axis component of 7-order harmonic current on a given value of a q-axis component of fundamental current of a current loop to obtain a given value i of a d-axis component of the current loop_{q_ref}(ii) a Then, the d-axis component given value and the q-axis component given value of the current loop are respectively used as the input quantity of the d-axis current loop and the q-axis current loop to carry out closed-loop control on the d-axis component and the q-axis component corresponding to the sampling current, and finally, the output quantity u of the d-axis current loop and the output quantity u of the q-axis current loop are respectively obtained_dAnd u_q。

And (4) performing closed-loop control on the d-axis component and the q-axis component corresponding to the sampling current by respectively using the d-axis component given value and the q-axis component given value of the current loop as input quantities of the d-axis current loop and the q-axis current loop, and controlling by adopting a proportional-integral regulator.

Accordingly, a computer-readable storage medium having stored thereon a harmonic current injection control program for suppressing vehicle low-speed judder, the harmonic current injection control program executing the steps of the harmonic current injection method described above, is proposed.

The invention also provides a permanent magnet synchronous motor control device, which comprises a signal acquisition module, a memory, a processor, a controller and a harmonic current injection control program which is stored on the memory and can be operated on the processor, wherein the signal acquisition module is used for sampling motor state signals and sending the motor state signals to the processor, the processor operates the harmonic current injection control program to output voltage control signals and send the voltage control signals to the controller for controlling the voltage of the permanent magnet synchronous motor, and the harmonic current injection control program executes the steps in the harmonic current injection method.

Has the advantages that: compared with the prior art, the invention has the following advantages: the invention provides a relational expression of harmonic current and harmonic torque under an extreme low-speed working condition, further calculates given values of 5-order and 7-order harmonic currents required for inhibiting the low-speed jitter of a vehicle according to the equation, then converts the given values of the 5-order and 7-order harmonic currents into a fundamental wave coordinate system, and superposes the given values of the fundamental wave currents on the given value of the fundamental wave current as a fundamental wave current loop, and the superposed sum is used as the input quantity of current loop control. The harmonic current injection method can achieve a very good effect in the scene of restraining the vehicle from shaking at a very low speed.

Drawings

FIG. 1 is a control block diagram of a motor control device for suppressing 6 th order torque ripple under a low speed running condition of a vehicle according to the present invention;

FIG. 2 is a flow chart of a method for injecting harmonic current for suppressing 6 th order torque ripple of a vehicle under a low speed operation condition according to the invention.

Detailed Description

The technical solution of the present invention is further described below with reference to the accompanying drawings and examples.

The invention discloses a harmonic current injection method for inhibiting vehicle low-speed jitter, which comprises the following steps of:

(1) and (4) current conversion.

Firstly, U, V, W three-phase current of the permanent magnet synchronous motor is sampled, subjected to Clark conversion and Park conversion and then converted to a two-phase synchronous rotating coordinate system to obtain d-axis and q-axis components of total sampling current containing harmonic current, and feedback values i of the d-axis and q-axis components of the sampling current are obtained_{d_fdb}、i_{q_fdb}。

(2) And calculating a harmonic current given value.

The relation between parameters such as harmonic current, harmonic torque and the like of the embedded permanent magnet synchronous motor under the extremely-low speed operation condition (generally below 200 RPM) is proposed:

in the invention, aiming at the problem of low-speed vehicle shaking, higher harmonic waves above 6 th order have little influence, so that 11 th order harmonic current, 11 th order and 13 th order harmonic counter potentials and 12 th order torque T are used₁₂Neglected, the above formula changes as:

in the formula, T₆Representing 6 orders of torque, E_m1Representing the magnitude of the back-emf of the fundamental wave, E_m5Representing the counter potential amplitude of the 5 th harmonic, E_m7Representing the counter potential amplitude of the 7 th harmonic, I_m1Is the amplitude of the fundamental current, I_m5At 5 th harmonic current amplitude, T_eRepresenting electromagnetic torque, omega representing electrical angular velocity of the motor, and omega representing mechanical angular velocity of the motor; theta denotes the initial phase of the fundamental wave, n_pRepresenting the number of pole pairs, L, of the motor_dRepresenting the direct-axis inductance, L_qRepresenting quadrature inductance.

And T₆Expressed as:

wherein the content of the first and second substances,

i_d1＝I_m1 sinθ (4)

i_q1＝I_m1 cosθ (5)

i_d5＝I_m5 sin(6ωt+5θ+θ₅) (6)

i_q5＝I_m5 cos(6ωt+5θ+θ₅) (7)

in the formula [ theta ]₅Indicating the initial phase of the 5 th harmonic current.

Let i_d7＝0，i_q7When the equation is combined and the obtained i is solved by MATLAB as 0_d5，i_q5. Namely, on the premise that the given values of the d-axis component and the q-axis component of the 7 th harmonic current are set to be 0, the given values of the d-axis component and the q-axis component of the 5 th harmonic current are solved. The 4 values are used as harmonic current set values of current superposition, namely i_{d5th_ref}，i_{q5th_ref}，i_{d7th_ref}，i_{d7th_ref}。

Thereby obtain the numerical relation of harmonic current and each parameter under the extremely low speed operation operating mode, wherein n is the rotational speed, and omega is 2 pi n:

i_{d5th_ref}＝f₁(T₆,E_m5,E_m7,T_e,n)

i_{q5th_ref}＝g₁(T₆,E_m5,E_m7,T_e,n)

i_{d7th_ref}＝f₂(T₆,E_m5,E_m7,T_e,n)

i_{d7th_ref}＝g₂(T₆,E_m5,E_m7,T_e,n)

in order to simplify the calculation during actual injection, the given value of each subharmonic current required for inhibiting the low-speed vibration of the vehicle under different torque and different rotating speed working conditions can be calculated, and a two-dimensional table taking the torque and the rotating speed as horizontal and vertical coordinates is made based on the given value.

D-axis and q-axis component given value calculation of fundamental current:

the given values of the d-axis component and the q-axis component of the fundamental current are obtained by adopting a maximum torque current ratio (MTPA) algorithm, and can be obtained by searching a two-dimensional table with the torque Te and the rotating speed omega as horizontal and vertical coordinates according to the principle of the maximum torque current ratio:

u_{q1st_ref}＝(R_si_{q1st_ref}+L_qp)i_{q1st_ref}+ω(ψ_f+L_di_{d1st_ref}) (12)

wherein i_sIs the amplitude of the fundamental current, i_smaxThe maximum value of the phase current amplitude depends on the maximum current capacity which can be borne by the IGBT and the motor. u. of_smaxThe maximum value of the phase voltage amplitude depends on the voltage capability provided by the direct current bus, and p is a differential operator. i.e. i_{d1st_ref}Given value for d-axis fundamental current i_{q1st_ref}Given value for q-axis fundamental wave current, u_{d1st_ref}Terminal voltage, u, generated for d-axis fundamental current_{q1st_ref}Terminal voltage, T, generated for q-axis fundamental current_eIs an electromagnetic torque, L_dRepresenting the direct-axis inductance, L_qRepresenting quadrature inductance. R_sFor internal resistance of the stator of the machine, psi_fAnd omega represents the electrical angular velocity of the motor, which is the flux linkage value of the permanent magnet.

(3) The harmonic currents are transformed into a fundamental coordinate system.

And performing inverse Park transformation on the harmonic current obtained in the harmonic current given value calculation step, wherein the transformation angles adopted by the 5 th harmonic and the 7 th harmonic are-6 theta and +6 theta respectively, and obtaining the sine small signal alternating current pulsating quantity obtained by transforming the harmonic current to a fundamental wave coordinate system. And theta is an included angle between the fundamental wave synchronous rotating coordinate system and the static coordinate system.

And the d-axis component of the 5-order current harmonic, the q-axis component of the 5-order current harmonic, the d-axis component of the 7-order current harmonic and the q-axis component of the 7-order current harmonic are subjected to inverse Park transformation to a fundamental wave synchronous rotating coordinate system, and an alternating current pulse form given value of the d-axis component of the 5-order harmonic current, an alternating current pulse form given value of the q-axis component of the 5-order harmonic current, an alternating current pulse form given value of the d-axis component of the 7-order harmonic current and an alternating current pulse form given value of the q-axis component of the 7-order harmonic current in the fundamental wave synchronous rotating coordinate system are respectively obtained.

(4) And (4) adjusting and controlling a current loop.

Respectively superposing d-axis and q-axis component given values of 5-order and 7-order harmonic currents converted to the fundamental wave coordinate system obtained in the step of converting the harmonic currents to the fundamental wave coordinate system on d-axis and q-axis component given values of the fundamental wave currents, namely summing the d-axis component of the fundamental wave currents, the d-axis component of the 5-order harmonic currents converted to the fundamental wave coordinate system and the d-axis component of the 7-order harmonic currents, and recording the sum as a current loop d-axis component given value i_{d_ref}(ii) a Summing the q-axis component of the fundamental current with the q-axis component of the 5 th harmonic current and the q-axis component of the 7 th harmonic current transformed to the fundamental coordinate system, denoted as i_{q_ref}. Then, the d-axis component given value and the q-axis component given value of the current loop are respectively used as the input quantity of the d-axis current loop and the q-axis current loop for closed-loop control, as shown in figure 1, i in the figure_{d_fdb}、i_{q_fdb}Respectively sampling feedback values of d-axis and q-axis components of the current, and finally obtaining output u of the d-axis and q-axis current loops respectively_dAnd u_q. In this embodiment, PID closed-loop control is preferred, and other closed-loop controllers may be used instead.

The flow corresponding to steps (2) to (4) is shown in FIG. 2. Correspondingly, the permanent magnet synchronous motor control device comprises a signal acquisition module, a memory, a processor, a controller and a harmonic current injection control program which is stored on the memory and can be operated on the processor, wherein the signal acquisition module is used for sampling three-phase current signals and sending the three-phase current signals to the processor, the processor operates the harmonic current injection control program to output voltage control signals, the controller receives the voltage control signals sent by the processor and controls the voltage of the permanent magnet synchronous motor according to the voltage control signals, and the harmonic current injection control program executes the steps in the harmonic current injection method.

Although the above embodiments are described with respect to an interior permanent magnet synchronous motor as an example, those skilled in the art can apply the above harmonic current injection method to a surface-mounted ac motor or other types of ac motors by analogy under the teaching of the above detailed examples.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.