Permanent magnet synchronous motor speed regulation control method based on all-drive system theory

Abstract

The invention discloses a permanent magnet synchronous motor speed regulation control method based on an all-drive system theory. The method comprises the following steps that A, an affine nonlinear standard model is constructed, and whether a PMSM system is an under-actuated system or not is judged based on the affine nonlinear standard model; b, obtaining a pseudo-strict feedback standard system of the PMSM according to the affine nonlinear state space model of the PMSM, and converting the pseudo-strict feedback standard system into an all-drive system model of the PMSM; c, according to the PMSM all-drive system model, constructing an all-drive control law with an expected feature structure and a linear closed-loop steady system; and D, obtaining an expected coefficient matrix through calculation, finally obtaining an all-drive control law with an expected characteristic structure, and carrying out speed regulation control on the permanent magnet synchronous motor by using the all-drive control law. According to the all-drive characteristic of the PMSM nonlinear system, accurate control over the rotating speed ring of the permanent magnet synchronous motor can be achieved, and the dynamic performance and the steady-state performance of the permanent magnet synchronous motor are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a permanent magnet synchronous motor speed regulation control method based on full drive system theory. Background Art

[0002] Permanent magnet synchronous motors (PMSMs) have attracted widespread attention in research and engineering due to their unique advantages, including high efficiency, high torque coefficient, high torque-to-inertia ratio, gearbox-free low-speed operation, and exceptionally high torque. In new energy vehicles, PMSM usage is growing rapidly, far exceeding that of specialty motors such as AC asynchronous motors, dual-excitation motors, and DC motors. The widespread adoption of PMSMs has also led to higher requirements for their speed accuracy and stability.

[0003] In order to achieve high-performance control systems, it is very important to obtain accurate rotor position and speed information. In traditional control systems, rotor position and speed information can be obtained using mechanical sensors such as optical encoders. However, the installation of mechanical sensors will increase the cost of use, and the limitations of conditions such as temperature, humidity and vibration will have more stringent requirements on the use environment. Therefore, the combination of sensorless control and control methods in permanent magnet synchronous motors has become the focus of current attention and research.

[0004] As control strategies have gradually been optimized and improved, a number of optimized control algorithms have emerged, including adaptive sliding mode control, active disturbance rejection sliding mode control, and neural network sliding mode control. While these control strategies can improve system requirements, they place high demands on the accuracy of the system model and the correctness of its parameters. Due to the complex operating environment of permanent magnet synchronous motors and the high degree of coupling between mathematical model variables, the inherent complexity of PMSM speed regulation systems is difficult to precisely control, resulting in poor sliding mode control quality. Summary of the Invention

[0005] The purpose of the present invention is to provide a permanent magnet synchronous motor speed control method based on full drive system theory, which can realize precise control of the permanent magnet synchronous motor speed loop according to the full drive characteristics of the PMSM nonlinear system, and improve the dynamic performance and steady-state performance of the permanent magnet synchronous motor.

[0006] The present invention adopts the following technical solutions:

[0007] A permanent magnet synchronous motor speed control method based on full drive system theory includes the following steps:

[0008] A: Based on the PMSM power equation and torque equation, and according to the full-drive characteristics of the PMSM system model, an affine nonlinear state-space model of the PMSM under two-phase synchronous rotating coordinate axes is constructed. Based on the affine nonlinear state-space model, it is determined whether the PMSM system is underdriven. If the PMSM system is underdriven, proceed to step B. If the PMSM system is not underdriven, exit.

[0009] B: Based on the affine nonlinear state space model of PMSM, the state variables in the original affine nonlinear state space model of PMSM are replaced by replacement state variables through state transformation to obtain the pseudo-strict feedback standard system of PMSM and transform it into the full-drive system model of PMSM;

[0010] C: Based on the PMSM all-wheel drive system model, an all-wheel drive control law with a desired characteristic structure is constructed based on the desired coefficient matrix and replacement state variables. Then, a linear closed-loop steady-state system with the desired characteristic structure is constructed by constructing linear terms with the desired characteristic structure and combining them with the system's desired matrix. The desired coefficient matrix is ​​determined based on the generalized finite eigenvector matrix of the closed-loop system.

[0011] D: Based on the linear closed-loop steady-state system, by setting the internal parameters of the permanent magnet synchronous motor and the generalized finite eigenvector matrix of the closed-loop system, the desired coefficient matrix is ​​calculated, and finally an all-wheel drive control law with the desired characteristic structure is obtained. The all-wheel drive control law is used to control the speed of the permanent magnet synchronous motor.

[0012] In step A, the voltage mathematical model of the PMSM in the three-phase stationary coordinate system is first constructed, and then the voltage mathematical model in the two-phase stationary coordinate system is obtained through vector transformation and converted into a state space form; then the current mathematical model in the synchronous rotating coordinate system is obtained based on the state space form and converted into a state space form, and the voltage mathematical model in the synchronous rotating coordinate system is obtained after sorting and simplification, thereby constructing the state space model of the PMSM in the two-phase synchronous rotating coordinate axis; finally, the state space model is converted into an affine nonlinear state space model of the PMSM.

[0013] Step A includes the following steps:

[0014] A1: Based on the PMSM's power and torque equations, combined with Kirchhoff's voltage law, we construct a voltage loop equation for a single winding of a permanent magnet synchronous motor, consisting of the voltage generated by the motor winding and winding flux. This allows us to derive the PMSM's voltage mathematical model in a three-phase stationary coordinate system.

[0015] A2: Project the three-phase stationary coordinate system of the permanent magnet synchronous motor onto the two-phase stationary coordinate system, and use the voltage vector value of the three-phase stationary coordinate system to represent the vector value of the two-phase stationary coordinate system. This converts the voltage mathematical model of the PMSM in the three-phase stationary coordinate system into the voltage mathematical model of the two-phase stationary coordinate system. Then, use the Clark vector control variation method to convert the voltage mathematical model in the two-phase stationary coordinate system into the state space form of the two-phase stationary coordinate system.

[0016] A3: Using the Park vector transformation control method, the state space form in the two-phase stationary coordinate system is transformed into the current mathematical model in the synchronous rotating coordinate system through projection transformation, and then transformed into the state space form in the synchronous rotating coordinate system;

[0017] A4: The state space form in the synchronously rotating coordinate system is simplified and sorted to obtain the voltage mathematical model in the synchronously rotating coordinate system.

[0018] A5: Based on the vector coordinate transformation from steps A2 to A4, a state space model of the PMSM under two-phase synchronous rotating coordinate axes is constructed;

[0019] A6: The state space model under the two-phase synchronous rotating coordinate axis is converted into an affine nonlinear state space model of the PMSM. The affine nonlinear state space model consists of a first nonlinear part containing state variables and a first control input part containing control inputs.

[0020] A7: Convert the affine nonlinear state-space model into a pseudo-strict state-space model in matrix form. Then, determine whether the PMSM system is under-actuated based on whether the rank of the coefficient matrix of the state variables in the pseudo-strict state-space model is greater than the rank of the coefficient matrix of the control input. If so, the system is under-actuated and proceeds to step B. If not, the system is not under-actuated and exits directly.

[0021] In step B, the original state variables of the affine nonlinear state space model of the PMSM are transformed by a set nonzero constant determinant matrix to obtain replacement state variables. The single-mode matrix is ​​a matrix with a nonzero constant determinant whose matrix determinant is 1.

[0022] Step B includes the following steps:

[0023] B1: The original state variables of the PMSM's affine nonlinear state space model are transformed by a set nonzero constant determinant matrix to obtain simplified replacement state variables;

[0024] B2: Substituting the original state variables in the affine nonlinear state space model of the PMSM with the replacement state variables to obtain a pseudo-strict feedback standard system. Expanding the pseudo-strict feedback standard system yields an expanded form of the pseudo-strict feedback standard system containing the first subsystem and the second subsystem.

[0025] B3: Based on the expansion of the pseudo-strict feedback standard system and adopting a control strategy with zero d-axis current, the PMSM pseudo-strict feedback standard system is transformed into a PMSM full-drive system model. The PMSM full-drive system model consists of a second nonlinear part containing replacement state variables and a second control input part containing control inputs.

[0026] In step C, a control law with a desired characteristic structure is constructed based on a set full rank matrix, a desired coefficient matrix, replacement state variables, a second nonlinear part of the PMSM full-wheel drive system model containing replacement state variables, and external inputs.

[0027] In step C, the expected coefficient matrix is ​​calculated as follows:

[0028] c1: Construct the constraint matrices F and M that satisfy the desired poles of the system. The generalized finite eigenvector matrix V(F, M) of the closed-loop system is calculated from the constraint matrices F and M, and the constraint matrix F is the Jordan standard form of the finite relative eigenvalues ​​of the closed-loop system.

[0029] c2: Construct a free constant parameter matrix so that the generalized finite eigenvector matrix V(F, M) satisfies the invertibility of the overall vector matrix;

[0030] c3: Calculate the expected coefficient matrix based on the set free constant parameter matrix.

[0031] Step D includes the following steps:

[0032] D1: Set the internal parameters of the permanent magnet synchronous motor;

[0033] D2: Set the constraint matrices F and M and the free constant parameter matrix;

[0034] D3: Based on the constraint matrices F and M and the free constant parameter matrix, calculate the expected coefficient matrix of the replacement state variables of the linear closed-loop system;

[0035] D4: Using the obtained desired coefficient matrix of the replacement state variables, combined with the known full-rank matrix, the replacement state variables, the second nonlinear part of the PMSM all-wheel drive system model containing the replacement state variables, and the external input, the all-wheel drive control law with the desired characteristic structure is calculated.

[0036] D5: Use the full-drive control law to control the speed of the permanent magnet synchronous motor.

[0037] In step D, the internal parameters of the permanent magnet synchronous motor include stator resistance, stator inductance, rotor inductance, number of magnetic pole pairs, permanent magnet flux and moment of inertia.

[0038] The present invention aims at the two major characteristics of PMSM speed instability and anti-interference, and changes the extreme points of the permanent magnet synchronous motor model through the full-drive system method, thereby effectively controlling the speed of the permanent magnet synchronous motor. The mathematical model of the permanent magnet synchronous motor belonging to the under-driven system constructed based on the power equation and the torque equation is transformed into a full-drive system model through elimination and order raising. Then, the full-drive control law is applied to the full-drive system, which can offset the nonlinear terms in the full-drive system of the permanent magnet synchronous motor and configure linear terms with the desired characteristic structure, thereby converting the PMSM system into a linear steady-state system, reducing the difficulty and computational complexity of the controller design. Compared with traditional control methods, the present invention not only ensures the full-drive characteristics of the system, but also increases the control accuracy and robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the process of the present invention;

[0040] Figure 2 Schematic diagram of the transformation of PMSM from a three-phase stationary coordinate system to a two-phase stationary coordinate system;

[0041] Figure 3 Schematic diagram of the transformation of PMSM from a two-phase stationary coordinate system to a two-phase rotating coordinate system;

[0042] Attachment Figure 4 It is the quadrature axis (q axis) equivalent circuit diagram of PMSM in the rotating coordinate system;

[0043] Attachment Figure 5 This is the direct axis (d-axis) equivalent circuit diagram of PMSM in the rotating coordinate system. DETAILED DESCRIPTION

[0044] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0045] like Figures 1 to 5 As shown, the permanent magnet synchronous motor speed control method based on the full-drive system theory of the present invention includes the following steps in sequence:

[0046] A: Based on the PMSM power equation and torque equation, and according to the full-drive characteristics of the PMSM system model, an affine nonlinear state-space model of the PMSM under two-phase synchronously rotating (dq) coordinate axes is constructed. Based on the affine nonlinear state-space model, it is determined whether the PMSM system is underdriven. If the PMSM system is underdriven, proceed to step B. If the PMSM system is not underdriven, exit.

[0047] In the present invention, the voltage mathematical model of the PMSM in a three-phase stationary coordinate system can be first obtained based on the power equation and torque equation of the PMSM in combination with Kirchhoff's voltage law (KVL); then, the mathematical model of the PMSM in the three-phase stationary coordinate system is converted into a mathematical model in a two-phase stationary coordinate system through vector transformation, and the mathematical model in the two-phase stationary coordinate system is converted into a state space form through the Clark vector control change method; then, the state space form in the two-phase stationary coordinate system is converted into a mathematical model in a synchronously rotating (dq) coordinate system through projection transformation through the Park vector transformation control method, and then converted into a state space form of the mathematical model in the synchronously rotating (dq) coordinate system, and the voltage mathematical model in the synchronously rotating coordinate system is obtained by sorting and simplifying, thereby constructing a state space model of the PMSM in the two-phase synchronously rotating (dq) coordinate axis; finally, the state space model is converted into an affine nonlinear state space model of the PMSM, and the affine nonlinear state space model of the PMSM includes a first nonlinear part and a first control input part;

[0048] In the present invention, step A comprises the following specific steps:

[0049] A1: Based on the PMSM's power and torque equations, combined with Kirchhoff's voltage law (KVL), we construct a voltage loop equation for a single winding of a permanent magnet synchronous motor, consisting of the voltage generated by the motor winding and winding flux. This allows us to derive the PMSM's voltage mathematical model in a three-phase stationary coordinate system.

[0050]

[0051] Among them, u a 、u b 、u c They are the voltages of the three-phase windings, R a 、R b 、R c are the resistance of the three-phase windings, i a 、i b 、i c are the currents of the three-phase windings, ψ a , ψ b , ψ c are the flux linkages of the corresponding phases in the three-phase winding in the three-phase stationary coordinate system;

[0052] In the present invention, based on the fact that the flux of the three-phase winding is composed of the flux generated by the stator winding current itself, the coupled flux generated by the other two phase windings (related to the instantaneous value of the three-phase current), and the flux coupled to the stator by the rotor permanent magnet (which changes periodically with the rotor position, exhibits a three-phase sinusoidal form, and has the same phase as the rotor electrical angle), a flux composition equation for the three-phase winding is constructed;

[0053]

[0054] Where, L A , L B , L C are the self-inductance coefficients of the three-phase stator windings, M XY is the mutual inductance coefficient of the corresponding XY two-phase winding, XY represents the subscripts AB, BC, AC, BA, CB, CA, respectively, ψ f is the permanent magnet flux, and θ is the angle between the rotor's d-axis and the stator's A-axis.

[0055] A2: If Figure 2 As shown, the voltage mathematical model of the PMSM in the three-phase stationary coordinate system in step A1 is vector-transformed, that is, the three-phase stationary (ABC) coordinate system of the permanent magnet synchronous motor is projected onto the two-phase stationary (α-β) coordinate system, and the voltage vector value of the three-phase stationary coordinate system is used to represent the vector value of the two-phase stationary coordinate system; then, the voltage mathematical model of the PMSM in the three-phase stationary coordinate system is transformed into the voltage mathematical model in the two-phase stationary coordinate system:

[0056]

[0057] Then, Clark vector control variation method is used to transform the voltage mathematical model in the above two-phase stationary coordinate system into the state space form in the two-phase stationary coordinate system:

[0058]

[0059] Where u α 、u β are the voltages of the two-phase stationary coordinate system respectively; the matrix C 3s / 2s represents the Clark transformation matrix, Indicates Clark vector control variation method; subscript 3s indicates three-phase stationary coordinate system; subscript 2s indicates two-phase stationary coordinate system;

[0060] A3: If Figure 3 As shown, through the Park vector transformation control method, the state space form of the two-phase stationary coordinate system obtained in step A2 is transformed into the current mathematical model in the synchronous rotating (dq) coordinate system through projection transformation:

[0061]

[0062] The Park vector transformation control method is used to transform the three-phase stationary coordinate system into the two-phase synchronous rotating coordinate system. Since the two-phase stationary coordinate system is used as the medium, it is equivalent to performing two linear transformations, that is,

[0063]

[0064] Where i d ,i q are the stator currents of the d-axis and q-axis in the rotating coordinate system, i α 、i β The stator current in the two-phase stationary coordinate system is converted into the state space form in the synchronous rotating coordinate system by converting the current mathematical model in the two-phase rotating (dq) coordinate system into the form of:

[0065]

[0066] In the formula, the matrix C 2r / 2s represents the Park transformation matrix, Indicates the Park vector control change method; the subscript 2r indicates the two-phase rotating coordinate system;

[0067] A4: The state space form in the synchronously rotating (dq) coordinate system is simplified and sorted to obtain the voltage mathematical model in the synchronously rotating coordinate system.

[0068]

[0069] Among them, u d 、u q represents the stator voltage, R s represents the stator resistance, ψ d , ψ q represents the stator flux, ω e represents the angular velocity of magnetic flux rotation, and the subscripts d and q in each physical quantity refer to the direct axis component and quadrature axis component in the synchronous rotating coordinate system, respectively; represents the first derivative of the stator flux;

[0070] In this embodiment, the state space form of the mathematical model in the two-phase synchronous rotation (dq) coordinate system obtained after Clark transformation and Park transformation can be converted into the stator voltage balance equation in the dq coordinate system. Since the d-axis voltage equation is composed of the motor's own winding voltage, the voltage generated by the d-axis flux, and the voltage generated by the q-axis coupled flux, and the q-axis voltage equation has the same principle as the d-axis, its equivalent circuit diagram is shown in the attached figure. Figure 4 and Figure 5Based on the above principle, the state space model of the voltage mathematical model in the synchronous rotating (dq) coordinate system can be sorted and simplified.

[0071] A5: Based on the vector coordinate transformation from steps A2 to A4, the state space model of the PMSM under the two-phase synchronous rotation (dq) coordinate axis is constructed as follows:

[0072]

[0073] Among them, i d ,i q are the stator currents of the d-axis and q-axis in the rotating coordinate system respectively; R s is the stator resistance; L d ,L q is the stator inductance in the rotating coordinate system; P is the number of magnetic poles of the permanent magnet synchronous motor; ω e is the angular velocity of rotation; ψ f is the permanent magnet flux; f v is the damping coefficient; C L is the load torque of the rotor. V d 、V q is the control input voltage in the rotating coordinate system; are the first-order derivatives of the stator current along the d-axis and q-axis in the rotating coordinate system respectively; is the first derivative of the angular velocity; J is the moment of inertia of the system.

[0074] A6: Convert the state space model of the PMSM obtained in step A5 under the two-phase synchronous rotation (dq) coordinate axis into the affine nonlinear state space model of the PMSM. The affine nonlinear state space model of the PMSM includes the first nonlinear part f(x, t) and the first control input part B(x, t)u. The affine nonlinear state space model of the PMSM is

[0075] Among them, the state variable x=[i d i q ω e ] T , control input u=[V d V q ] T ;

[0076]

[0077] In f(x,t), x1, x2, and x3 are i d ,i q ,ω e , L d ,L qis the stator inductance of PMSM in the rotating coordinate system, the matrix [V d V q ] T The superscript T represents the transpose of the matrix. t represents the time independent variable of the original state variable in the nonlinear part. middle is the first-order derivative of x; E is the identity matrix.

[0078] A7: Convert the affine nonlinear state space model of the PMSM obtained in step A6 into a pseudo-rigid state space model in the following matrix form: Then, based on whether the rank of the coefficient matrix A(x, t) of the state variable x in the pseudo-strict state space model is greater than the rank of the coefficient matrix B(x, t) of the control input u, determine whether the PMSM system is an underactuated system; if it is greater, it is an underactuated system and proceeds to step B; if it is less, it is a non-underactuated system and exits directly;

[0079] An underactuated system is a dynamic system in which the number of independent control inputs is less than the number of degrees of freedom. Underactuated systems cannot achieve instantaneous and arbitrary adjustment of all degrees of freedom through direct control. Therefore, the present invention determines the type of PMSM system and adopts the corresponding control method to accurately control the PMSM speed.

[0080] In this embodiment,

[0081]

[0082] The rank of a matrix describes its linear independence and is the maximum number of linearly independent groups of row (or column) vectors in the matrix. In this embodiment, since the rank of matrix A(x, t) is 3, which is greater than the rank of matrix B(x, t) is 2, the PMSM system is underdriven, and the process proceeds to step B.

[0083] In the present invention, determining whether the PMSM system is an under-driven system through step A can lay the foundation for solving the PMSM full-drive system model in the subsequent steps.

[0084] B: According to the affine nonlinear state space model of the PMSM under the two-phase synchronous rotation (dq) coordinate axis obtained in step A, the state variables in the original PMSM's affine nonlinear state space model are replaced by replacement state variables through state transformation, that is, the replacement state variable z is linearly transformed into the original state variable x through the single-mode matrix Q to obtain the pseudo-strict feedback standard system of the PMSM, and the pseudo-strict feedback standard system is converted into the full-drive system model of the PMSM.

[0085] In the present invention, step B comprises the following steps:

[0086] B1: Based on the affine nonlinear state space model of the PMSM obtained in step A6, the nonzero constant determinant matrix is ​​set Performing a transformation on the original state variable x of the affine nonlinear state space model of the PMSM to obtain a simplified replacement state variable z;

[0087] In step B1, the non-zero constant determinant matrix (i.e., single-mode matrix) is set satisfy That is, the unimodular matrix Q is a matrix satisfying a non-zero constant determinant whose matrix determinant is 1;

[0088] Among them, the full rank matrix G after block division satisfies the determinant detG≠0; x (0～1) Represents the zero-order and first-order derivatives of the original state variable x; represents the block form of the coefficient matrix of the control input u in the pseudo-strict feedback standard system;

[0089] In this embodiment, in order to simplify the state variables of the affine nonlinear state space model of the PMSM and increase the order of the affine nonlinear state space model, the state variables of the affine nonlinear state space model of the PMSM are converted according to the following method, thereby completing the conversion from the original state variable x to the replacement state variable z.

[0090] First, the single-mode matrix Q is divided into blocks to obtain [Q1 Q2] T , where Q1∈R 1×3 , Q2∈R 2×3 ; That is, Q1 is the first block matrix with 1 row and 3 columns, and Q2 is the second block matrix with 2 rows and 3 columns;

[0091] Then, the original state variable x is multiplied by the single-module matrix Q to obtain the simplified replacement state variable z;

[0092]

[0093] In the present invention, the replacement state variable z is used as the transformed first subsystem Z I and the second subsystem Z II The state variables of I =z1;Z II =[z2 z3] T , z1, z2, z3 are the replacement state variables after transformation, and the relationship between them and the original state variable x is

[0094] B2: Use the simplified replacement state variable z obtained in step B1 to replace the original state variable x in the affine nonlinear state space model of the PMSM obtained in step A6 to obtain the pseudo-strict feedback standard system:

[0095]

[0096] In step B2, combined with the affine nonlinear state space model of the PMSM obtained in step A, the above pseudo-strict feedback standard system is expanded to obtain the expanded formula:

[0097]

[0098] in,

[0099] N=z2+z3; u=[V d V q ] T ;

[0100] The pseudo strict feedback standard system formed after the transformation of the affine nonlinear state space model of PMSM consists of two subsystems. The first subsystem Z Ι and the second subsystem Z ΙΙ , represents the first-order derivative of the first subsystem; represents the first-order derivative of the second subsystem; z1 becomes the transformed first subsystem Z Ι The state variables z2 to z3 become the transformed second subsystem Z ΙΙ The state vector of v represents the time variable that replaces the state variable z, z 1～3 represents the replacement of state variables z1 to z3, represents z 1～3 The first derivative of ;

[0101] B3: Based on the expansion of the pseudo-strict feedback standard system obtained in step B2, since in the permanent magnet synchronous motor control, the d-axis current does not provide torque for the PMSM rotation, the existence of the d-axis current will reduce the output efficiency of the PMSM maximum torque, increase the copper loss of the PMSM and make the control algorithm complicated, so the i-axis current can be used in the two-phase rotating coordinate system. d =0 control strategy, at this time z3 = 0, so we can get [z1 z2] = [i q ω e ], transforming the PMSM pseudo-strict feedback standard system into a PMSM full-drive system model is the second nonlinear part, Gu is the second control input part;

[0102] in,

[0103] T=L d -L q; u=[V d V q ] T ;

[0104] Step B completes the main part of the all-wheel drive controller design. Using the affine nonlinear state space model of the PMSM under the two-phase synchronous rotation (dq) coordinate axis obtained in step A, the replacement state variable z is linearly transformed by the single-mode matrix Q on the original state variable x through state transformation, and i is used to replace the state variable z. d = 0 control strategy offsets the replacement state variable z3, thereby increasing the order of the affine nonlinear state space model and reducing the number of system state variables, effectively reducing the control difficulty of the system. Compared with traditional control methods, the present invention can not only maintain the all-wheel drive characteristics of the original system, but also enable the controller to more accurately control the system state variables, thereby enhancing robustness.

[0105] C: Based on the PMSM all-wheel drive system model obtained in step B, construct an all-wheel drive control law with the desired characteristic structure to offset the second nonlinear part of the PMSM all-wheel drive system; the all-wheel drive control law is based on the desired coefficient matrix A 0～1 and replace the state variable z to construct the expected coefficient matrix A 0～1 The generalized finite eigenvector matrix V(M,F) of the closed-loop system is determined; then, a linear term with the desired characteristic structure is constructed and combined with the desired coefficient matrix A 0～1 Construct a linear closed-loop steady-state system with desired characteristic structure;

[0106] Among them, A 0～1 is the expected coefficient matrix of the linear closed-loop system replacing the state variable z obtained by designing the control law;

[0107] In step C, the control law with the desired characteristic structure is applied as Used to offset the second nonlinear part in the PMSM full drive system; then construct a linear term with the desired characteristic structure, thereby obtaining a linear steady-state closed-loop system with the desired characteristic structure

[0108] Among them, B -1 (·) represents the full-rank matrix G after block partitioning in step B2, w is the external input, z 1～2 represents the replacement of state variables z1 to z2, represents z 1～2 The first derivative of represents z 1～2 The second derivative of

[0109] In this embodiment, the method for solving A0 and A1 is as follows:

[0110] c1: Construct two constraint matrices F and M that satisfy the desired poles of the system. The matrix V(M,F) is the generalized finite eigenvector matrix of the closed-loop system and is calculated from the 3-row, 3-column constraint matrix F and the 2-row, 1-column constraint matrix M.

[0111] Right now:

[0112] where the constraint matrix F is the Jordan standard form of the finite relative eigenvalues ​​of the closed-loop system, R represents a real number, [M MF] T The superscript T in [M MF] indicates the transpose of the matrix [M MF].

[0113] c2: Construct a 2-row and 1-column free constant parameter matrix V ∞ , so that the generalized finite eigenvector matrix V(M,F) of the closed-loop system satisfies the reversibility of the overall vector matrix, that is, det[V(M,F)]≠0;

[0114]

[0115] c3: Calculate the replacement state variable expected coefficient matrix A of the linear closed-loop system obtained in step C1 0～1 ;

[0116]

[0117] Among them, m 1～3 、W ∞ 、V ∞ ∈R 2×1 , ρ 1～3 ∈R 2×2 is the set free constant parameter matrix.

[0118] Designing a control law with the desired characteristic structure in step C is the core of the all-wheel drive system method. By designing the all-wheel drive control law, the second nonlinear component of the PMSM all-wheel drive system is offset. By constructing linear terms with the desired characteristic structure, the nonlinear, strongly coupled PMSM all-wheel drive system is transformed into a linear steady-state closed-loop system. Compared to traditional control methods for nonlinear systems, this method can effectively reduce the computational effort and complexity of controller design.

[0119] D: Based on the linear closed-loop steady-state system obtained in step C, by setting the internal parameters of the permanent magnet synchronous motor and the generalized finite eigenvector matrix V(M,F) of the closed-loop system, the expected coefficient matrix A that replaces the state variable z in the linear closed-loop system is calculated. 0～1 , and finally obtain the full-drive control law with the desired characteristic structure, and use the full-drive control law to control the speed of the permanent magnet synchronous motor;

[0120] Among them, the internal parameters of the permanent magnet synchronous motor include stator resistance, stator inductance, rotor inductance, pole pair number, permanent magnet flux and moment of inertia; As can be seen from the above, the expected coefficient matrix A can be calculated by setting the generalized finite eigenvector matrix V(M,F) 0～1 , and then combined with the replacement of the state variable z in the linear closed-loop system, the full-wheel drive control law with the desired characteristic structure can be finally obtained. The generalized finite eigenvector matrix V(M,F) is composed of the free constant parameter matrix m 1～3 、W ∞ 、V ∞ , ρ 1～3 Sure.

[0121] The step D comprises the following specific steps:

[0122] D1: Set the internal parameters of the permanent magnet synchronous motor to stator resistance, stator inductance, rotor inductance, number of magnetic pole pairs, permanent magnet flux and moment of inertia;

[0123] D2: Set the constraint matrices F and M to ensure that the obtained linear closed-loop steady-state system has a stable characteristic structure; at the same time, set the free constant parameter matrix m 1～3 、W ∞ 、V ∞ and ρ 1～3 ;

[0124] D3: According to the constraint matrices F and M, the free constant parameter matrix m 1～3 、W ∞ 、V ∞ and ρ 1～3 And the known unit matrix E, the replacement state variable expected coefficient matrix A of the linear closed-loop system is calculated 0～1 ;

[0125] In this embodiment, since the constraint matrices F and M, and the free constant parameter matrix m 1～3 、W ∞ 、V ∞ and ρ 1～3 And the unit matrix E are known, according to the above calculation formula The expected coefficient matrix A of the replacement state variable can be obtained by solving 0～1 ;

[0126] D4: Use the obtained replacement state variable expected coefficient matrix A 0～1 , combined with the replacement state variable z in the linear closed-loop system, the full-drive control law and the linear closed-loop steady-state system with the desired characteristic structure are calculated;

[0127] In this embodiment, since B -1 (·), z 1～2 All are known, The second nonlinear part known in step B3 can be Calculated, and the external input w is 0, so based on the replacement state variable expectation coefficient matrix A 0～1 , the all-wheel drive control law with the desired characteristic structure can be calculated.

[0128]

[0129] D5: Use the full-drive control law to control the speed of the permanent magnet synchronous motor.

[0130] The present invention breaks with traditional controller design thinking, fully utilizing the system's entire state information and state inputs, and providing the system with sufficient degrees of freedom based on the full-drive characteristics of nonlinear systems. Traditional control methods, due to the nonlinear, strongly coupled, and multivariable nature of the PMSM, lead to complex controller design, disrupting the full-drive characteristics of the PMSM system, resulting in poor control effectiveness during the control process. However, the present invention, by designing a corresponding full-drive control law, can offset the nonlinear terms in the permanent magnet synchronous motor full-drive system and configure linear terms with the desired characteristic structure, thereby transforming the PMSM system into a linear steady-state system, reducing the difficulty of controller design and computational complexity.

[0131] Likewise, although the present disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art after reading and understanding the specification and drawings. The present disclosure includes all such modifications and variations and is limited only by the scope of the claims. In particular, with respect to the various functions performed by the components described above (e.g., elements, resources, etc.), unless otherwise indicated, the terms used to describe such components are intended to correspond to any component (functionally equivalent) that performs the specific functions of the described components, even if structurally not equivalent to the disclosed structures. In addition, although specific features of the present disclosure may have been disclosed with respect to only one of several implementations, such features may be combined with one or more other features of other implementations as may be desired and beneficial for any given or specific application. In addition, with respect to the terms "including," "having," "having," "having," or variations thereof used in the specific embodiments or claims, such terms are intended to be inclusive in a manner similar to the term "comprising."

[0132] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0133] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A permanent magnet synchronous motor speed control method based on full drive system theory, characterized in that: The following steps are involved: A: Based on the PMSM power equation and torque equation, and according to the full-drive characteristics of the PMSM system model, an affine nonlinear state-space model of the PMSM under two-phase synchronous rotating coordinate axes is constructed. Based on the affine nonlinear state-space model, it is determined whether the PMSM system is underdriven. If the PMSM system is underdriven, proceed to step B. If the PMSM system is not under-driven, exit; B: Based on the affine nonlinear state space model of PMSM, the state variables in the original affine nonlinear state space model of PMSM are replaced by replacement state variables through state transformation to obtain the pseudo-strict feedback standard system of PMSM and transform it into the full-drive system model of PMSM; C: Based on the PMSM all-wheel drive system model, an all-wheel drive control law with a desired characteristic structure is constructed based on the desired coefficient matrix and replacement state variables. Then, a linear closed-loop steady-state system with the desired characteristic structure is constructed by constructing linear terms with the desired characteristic structure and combining them with the system's desired matrix. The desired coefficient matrix is ​​determined based on the generalized finite eigenvector matrix of the closed-loop system. D: Based on the linear closed-loop steady-state system, by setting the internal parameters of the permanent magnet synchronous motor and the generalized finite eigenvector matrix of the closed-loop system, the desired coefficient matrix is ​​calculated, and finally an all-wheel drive control law with the desired characteristic structure is obtained. The all-wheel drive control law is used to control the speed of the permanent magnet synchronous motor.

2. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: In step A, the voltage mathematical model of the PMSM in the three-phase stationary coordinate system is first constructed, and then the voltage mathematical model in the two-phase stationary coordinate system is obtained through vector transformation and converted into a state space form; then the current mathematical model in the synchronous rotating coordinate system is obtained based on the state space form and converted into a state space form, and the voltage mathematical model in the synchronous rotating coordinate system is obtained after sorting and simplification, thereby constructing the state space model of the PMSM in the two-phase synchronous rotating coordinate axis; finally, the state space model is converted into an affine nonlinear state space model of the PMSM.

3. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: Step A includes the following steps: A1: Based on the PMSM's power and torque equations, combined with Kirchhoff's voltage law, we construct a voltage loop equation for a single winding of a permanent magnet synchronous motor, consisting of the voltage generated by the motor winding and winding flux. This allows us to derive the PMSM's voltage mathematical model in a three-phase stationary coordinate system. A2: Project the three-phase stationary coordinate system of the permanent magnet synchronous motor onto the two-phase stationary coordinate system, and use the voltage vector value of the three-phase stationary coordinate system to represent the vector value of the two-phase stationary coordinate system. This converts the voltage mathematical model of the PMSM in the three-phase stationary coordinate system into the voltage mathematical model of the two-phase stationary coordinate system. Then, use the Clark vector control variation method to convert the voltage mathematical model in the two-phase stationary coordinate system into the state space form of the two-phase stationary coordinate system. A3: Using the Park vector transformation control method, the state space form in the two-phase stationary coordinate system is transformed into the current mathematical model in the synchronous rotating coordinate system through projection transformation, and then transformed into the state space form in the synchronous rotating coordinate system; A4: The state space form in the synchronously rotating coordinate system is simplified and sorted to obtain the voltage mathematical model in the synchronously rotating coordinate system. A5: Based on the vector coordinate transformation from steps A2 to A4, a state space model of the PMSM under two-phase synchronous rotating coordinate axes is constructed; A6: The state space model under the two-phase synchronous rotating coordinate axis is converted into an affine nonlinear state space model of the PMSM. The affine nonlinear state space model consists of a first nonlinear part containing state variables and a first control input part containing control inputs. A7: Convert the affine nonlinear state-space model into a pseudo-strict state-space model in matrix form. Then, determine whether the PMSM system is under-actuated based on whether the rank of the coefficient matrix of the state variables in the pseudo-strict state-space model is greater than the rank of the coefficient matrix of the control input. If so, the system is under-actuated and proceeds to step B. If not, the system is not under-actuated and exits directly.

4. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: In step B, the original state variables of the affine nonlinear state space model of the PMSM are transformed by a set nonzero constant determinant matrix to obtain replacement state variables. The single-mode matrix is ​​a matrix with a nonzero constant determinant whose matrix determinant is 1.

5. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: Step B includes the following steps: B1: The original state variables of the PMSM's affine nonlinear state space model are transformed by a set nonzero constant determinant matrix to obtain simplified replacement state variables; B2: Substituting the original state variables in the affine nonlinear state space model of the PMSM with the replacement state variables to obtain a pseudo-strict feedback standard system. Expanding the pseudo-strict feedback standard system yields an expanded form of the pseudo-strict feedback standard system containing the first subsystem and the second subsystem. B3: Based on the expansion of the pseudo-strict feedback standard system and adopting a control strategy with zero d-axis current, the PMSM pseudo-strict feedback standard system is transformed into a PMSM full-drive system model. The PMSM full-drive system model consists of a second nonlinear part containing replacement state variables and a second control input part containing control inputs.

6. The permanent magnet synchronous motor speed control method according to claim 5, characterized in that: In step C, a control law with a desired characteristic structure is constructed based on a set full rank matrix, a desired coefficient matrix, replacement state variables, a second nonlinear part of the PMSM full-wheel drive system model containing replacement state variables, and external inputs.

7. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: In step C, the expected coefficient matrix is ​​calculated as follows: c1: Construct a constraint matrix that satisfies the desired extremes of the system F and M , the generalized finite eigenvector matrix of the closed-loop system V ( F , M ) by the constraint matrix F and M Calculate and obtain, and the constraint matrix F is the Jordan standard form of the finite relative eigenvalues ​​of the closed-loop system; c2: Construct a free constant parameter matrix to make the generalized finite eigenvector matrix V ( F , M )Satisfies the invertibility of the overall vector matrix; c3: Calculate the expected coefficient matrix based on the set free constant parameter matrix.

8. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: Step D includes the following steps: D1: Set the internal parameters of the permanent magnet synchronous motor; D2: Set the constraint matrix F and M and the free constant parameter matrix; D3: According to the constraint matrix F and M and the free constant parameter matrix, calculate the replacement state variable expected coefficient matrix of the linear closed-loop system; D4: Using the obtained desired coefficient matrix of the replacement state variables, combined with the known full-rank matrix, the replacement state variables, the second nonlinear part of the PMSM all-wheel drive system model containing the replacement state variables, and the external input, the all-wheel drive control law with the desired characteristic structure is calculated. D5: Use the full-drive control law to control the speed of the permanent magnet synchronous motor.

9. The permanent magnet synchronous motor speed control method according to claim 1, characterized in that: In step D, the internal parameters of the permanent magnet synchronous motor include stator resistance, stator inductance, rotor inductance, number of magnetic pole pairs, permanent magnet flux and moment of inertia.

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