Permanent magnet synchronous motor sliding mode control method, device, equipment and storage medium

Abstract

The present invention relates to the technical field of permanent magnet synchronous motor control, and discloses a sliding mode control method, device, equipment and storage medium of a permanent magnet synchronous motor. The method comprises: constructing a motor state equation based on a permanent magnet synchronous motor mathematical model, treating the load torque as an external disturbance, and constructing a new adaptive nonlinear extended state observer; constructing a non-singular fast terminal sliding mode surface and a new variable gain exponential reaching law based on the motor state equation; constructing a new non-singular fast terminal sliding mode controller based on the new adaptive nonlinear extended state observer, the non-singular fast terminal sliding mode surface and the new variable gain exponential reaching law; and performing sliding mode control of a permanent magnet synchronous motor using the new non-singular fast terminal sliding mode controller. Compared with the existing known technology, the new sliding mode control strategy of the present invention not only greatly weakens the chattering and improves the control accuracy, but also significantly accelerates the convergence speed, so that the system can converge to an equilibrium point asymptotically within a limited time.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet synchronous motor control, and in particular to a permanent magnet synchronous motor sliding mode control method, device, equipment and storage medium. Background Art

[0002] Permanent Magnet Synchronous Motor (PMSM) is widely used in aerospace, high-speed trains and other fields due to its advantages such as high efficiency, high power density and high reliability. In the control method of permanent magnet synchronous motor servo system, the traditional PI control strategy is usually adopted. However, when the external disturbance changes suddenly, its performance is difficult to meet the requirements. Therefore, many scholars are exploring more and more effective control strategies.

[0003] In order to improve the position tracking performance of permanent magnet synchronous motors, many scholars at home and abroad have proposed many control methods, the main methods are anti-disturbance control, backstepping control, robust control, sliding mode control, etc. Among them, sliding mode control has attracted much attention due to its simple algorithm and strong robustness. However, traditional sliding mode control cannot guarantee that the system converges within a finite time, so some scholars have proposed terminal sliding mode control. In order to solve the singularity problem of terminal sliding mode control in second-order systems such as permanent magnet synchronous motors and make it converge quickly, some scholars have proposed non-singular fast terminal sliding mode control (NFTSMC), which makes the system converge to the equilibrium point within a finite time by designing a non-singular fast terminal sliding mode surface. At the same time, the sliding surface and the reaching law jointly determine the overall performance of the sliding mode control, among which the exponential reaching law has better performance, but the traditional exponential reaching law has large jitter and a slow approach speed.

[0004] However, the non-singular fast terminal sliding mode control does not consider the impact of external disturbance changes when it is designed, which will lead to reduced control accuracy when the load disturbance changes suddenly. For this reason, many scholars have designed observers to improve the system's anti-disturbance ability, among which the extended state observer is widely used due to its high precision and low computational complexity. However, the traditional linear extended state observer (LESO) and the nonlinear extended state observer (NESO) based on the fal function have low accuracy and slow convergence speed.

[0005] Therefore, how to improve the accuracy and robustness of the sliding mode control of permanent magnet synchronous motors and enhance the convergence speed, adaptability and response speed of the observer is a technical problem that needs to be solved urgently. Summary of the invention

[0006] The present invention provides a permanent magnet synchronous motor sliding mode control method, device, equipment and storage medium, aiming to solve at least one of the above technical problems.

[0007] To achieve the above object, the present invention provides a permanent magnet synchronous motor sliding mode control method, comprising the following steps:

[0008] Based on the mathematical model of permanent magnet synchronous motor, the motor state equation is constructed;

[0009] Based on the mathematical model of the permanent magnet synchronous motor, the load torque is regarded as an external disturbance, and a new adaptive nonlinear extended state observer is constructed;

[0010] Based on the motor state equation, a non-singular fast terminal sliding surface and a new variable gain exponential reaching law are constructed;

[0011] Based on the novel adaptive nonlinear extended state observer, the nonsingular fast terminal sliding mode surface and the novel variable gain exponential reaching law, a novel nonsingular fast terminal sliding mode controller is constructed;

[0012] The novel non-singular fast terminal sliding mode controller is used to perform sliding mode control of a permanent magnet synchronous motor.

[0013] Optionally, based on the permanent magnet synchronous motor mathematical model, the motor state equation is constructed, including:

[0014] Establishing voltage equations, torque equations and motion equations of the dq-axis stator and rotor, combining the deformed expression of the voltage equation with the torque equation and the motion equation, and establishing a mathematical model of the permanent magnet synchronous motor with the constraint that the d-axis stator flux is equal to the q-axis stator flux;

[0015] The expression of the mathematical model of the permanent magnet synchronous motor is specifically:

[0016]

[0017] In the formula, is the mechanical angular velocity of the rotor, is the polar logarithm, is the permanent magnet fundamental excitation magnetic field chain, is the q-axis stator current, is the friction coefficient, is the load torque, is the moment of inertia, and the d-axis stator flux is constrained to be equal to the q-axis stator flux, specifically: ;

[0018] Based on the mathematical model of permanent magnet synchronous motor, the motor state equation is constructed;

[0019] The expression of the motor state variable of the motor state equation is specifically:

[0020]

[0021]

[0022]

[0023] In the formula, is the expected value of the permanent magnet synchronous motor position.

[0024] Optionally, based on the permanent magnet synchronous motor mathematical model, the load torque is regarded as an external disturbance, and a new adaptive nonlinear extended state observer is constructed, which specifically includes:

[0025] The load torque is regarded as an external disturbance, and a new nonlinear extended state observer is constructed. The coefficients in the new nonlinear extended state observer are Replace with the adaptive coefficient, and update the new nonlinear extended state observer to obtain a new adaptive nonlinear extended state observer;

[0026] Among them, the expression of the new nonlinear extended state observer is:

[0027] In the formula, , , , , ; , NESO observed , The estimated value of , is the tracking error, where the estimation error There is an upper bound, that is, there is a constant ,make ;

[0028] Among them, the expression of the updated new adaptive nonlinear extended state observer is:

[0029]

[0030] In the formula, , .

[0031] Optionally, based on the motor state equation, a non-singular fast terminal sliding mode surface and a new variable gain exponential reaching law are constructed, specifically including:

[0032] Based on the set permanent magnet synchronous motor state variables, a non-singular fast terminal sliding surface and a new variable gain exponential reaching law are designed;

[0033] The expression of the non-singular fast terminal sliding surface is specifically:

[0034]

[0035] In the formula, is the expected value of the permanent magnet synchronous motor position, , , ; ;

[0036] The expression of the novel variable gain exponential reaching law is specifically:

[0037] In the formula, , , , , , , , for An increasing function that satisfies ; middle and Both is a decreasing function, then for The increasing function of .

[0038] Optionally, based on the novel adaptive nonlinear extended state observer, the nonsingular fast terminal sliding mode surface and the novel variable gain exponential reaching law, a novel nonsingular fast terminal sliding mode controller is constructed, specifically including:

[0039] The expression of the derivative of the non-singular fast terminal sliding mode surface is made equal to the expression of the novel variable gain exponential reaching law to obtain the initial novel non-singular fast terminal sliding mode controller; wherein the expression of the derivative of the non-singular fast terminal sliding mode surface is specifically:

[0040]

[0041] Among them, the expression of the initial new non-singular fast terminal sliding mode controller is:

[0042]

[0043] The load torque is estimated by using the novel adaptive nonlinear extended state observer, and the obtained load estimation value is added as a compensation term to the initial novel non-singular fast terminal sliding mode controller to obtain a final novel non-singular fast terminal sliding mode controller;

[0044] Among them, the final expression of the new non-singular fast terminal sliding mode controller is:

[0045]

[0046] In the formula, For load, Estimated value for load.

[0047] Optionally, the step of using the novel non-singular fast terminal sliding mode controller to perform a permanent magnet synchronous motor sliding mode control step specifically includes:

[0048] The steady-state error bound and convergence time of the generated novel non-singular fast terminal sliding mode controller are analyzed to determine whether the permanent magnet synchronous motor can converge to a stable state within a finite time under the action of the novel non-singular fast terminal sliding mode controller;

[0049] If so, the finally obtained novel non-singular fast terminal sliding mode controller is used as the permanent magnet synchronous motor sliding mode control execution.

[0050] In addition, in order to achieve the above object, the present invention also provides a permanent magnet synchronous motor sliding mode control device, comprising:

[0051] The first building module is used to build a motor state equation based on a permanent magnet synchronous motor mathematical model;

[0052] The second building module is used to construct a novel adaptive nonlinear extended state observer based on the permanent magnet synchronous motor mathematical model and regard the load torque as an external disturbance;

[0053] A third building module is used to construct a non-singular fast terminal sliding surface and a novel variable gain exponential reaching law based on the motor state equation;

[0054] A fourth building block is used to build a novel non-singular fast terminal sliding mode controller based on the novel adaptive nonlinear extended state observer, the non-singular fast terminal sliding mode surface and the novel variable gain exponential reaching law;

[0055] A control module is used to perform sliding mode control of a permanent magnet synchronous motor using the novel non-singular fast terminal sliding mode controller.

[0056] In addition, in order to achieve the above-mentioned purpose, the present invention also provides a permanent magnet synchronous motor sliding mode control device, which includes: a memory, a processor, and a permanent magnet synchronous motor sliding mode control program stored in the memory and executable on the processor. When the permanent magnet synchronous motor sliding mode control program is executed by the processor, the steps of the permanent magnet synchronous motor sliding mode control method as described above are implemented.

[0057] In addition, in order to achieve the above-mentioned purpose, the present invention also provides a storage medium, on which a permanent magnet synchronous motor sliding mode control program is stored. When the permanent magnet synchronous motor sliding mode control program is executed by a processor, the steps of the above-mentioned permanent magnet synchronous motor sliding mode control method are implemented.

[0058] The beneficial effects of the present invention are:

[0059] (1) A new adaptive nonlinear extended state observer is designed. This observer uses an improved function to replace the traditional fal function, which improves the convergence speed of the observer. At the same time, a variable coefficient term is used to replace the original fixed gain, making the observer more adaptive. The simulation shows that the convergence time of the new adaptive NESO is reduced by about 10% compared with the NESO and LESO based on the fal function. , , the estimation errors are reduced by about , .

[0060] (2) A new variable gain exponential reaching law is designed, which reduces the convergence time by about 10% compared with the ordinary exponential reaching law. , the sliding mode state error is reduced by about , with faster convergence speed, smaller jitter and stronger adaptability.

[0061] (3) A novel adaptive nonlinear extended state observer and a novel variable gain exponential reaching law are applied to PMSM position control to construct a new composite non-singular fast terminal sliding mode controller. Compared with the existing known technologies, the tracking convergence time of the controller for a given step position is reduced by about , with greater robustness and faster response speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A schematic diagram of the device structure of the hardware operating environment involved in the embodiment of the present invention;

[0063] Figure 2 A schematic diagram of a flow chart of an embodiment of a sliding mode control method for a permanent magnet synchronous motor according to the present invention;

[0064] Figure 3It is a flow chart of a specific example of sliding mode control of a permanent magnet synchronous motor of the present invention;

[0065] Figure 4 This is a structural block diagram of the vector control of the permanent magnet synchronous motor of the present invention;

[0066] Figure 5 The present invention provides Function graph;

[0067] Figure 6 A comparison diagram of the convergence speed between the novel variable gain exponential reaching law and the common exponential reaching law of the present invention;

[0068] Figure 7 It is a waveform diagram of the tracking situation of the new NFTSMC of the present invention and the common NFTSMC for a given position when no observer is included;

[0069] Figure 8 It is a waveform diagram comparing the position tracking errors of the new NFTSMC of the present invention and the common NFTSMC when no observer is included;

[0070] Fig. 9 This is a waveform diagram comparing the load torque estimation capabilities of the novel adaptive NESO, the NESO based on the fal function, and the LESO of the present invention;

[0071] Fig.10 The error waveforms of PMSM speed estimation using the novel adaptive NESO, NESO based on fal function and LESO of the present invention are shown respectively;

[0072] Fig.11 This is a waveform diagram comparing the tracking capabilities of the novel composite control strategy of the present invention and the common non-singular fast terminal sliding mode control strategy based on LESO for a given step position;

[0073] Fig.12 The novel composite control strategy of the present invention and the common non-singular fast terminal sliding mode control strategy based on LESO are given Position tracking waveform;

[0074] Fig.13 The novel composite control strategy of the present invention and the common non-singular fast terminal sliding mode control strategy based on LESO are given Position tracking error waveform

[0075] Fig.14 The present invention is a structural block diagram of a sliding mode control device for a permanent magnet synchronous motor in an embodiment of the present invention.

[0076] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0077] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0078] like Figure 1 As shown, Figure 1 It is a schematic diagram of the device structure of the hardware operating environment involved in the embodiment of the present invention.

[0079] like Figure 1 As shown, the device may include: a processor 1001, such as a CPU, a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a WI-FI interface). The memory 1005 may be a high-speed RAM memory, or it may be a stable memory (non-volatile memory), such as a disk memory. The memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0080] Those skilled in the art will understand that Figure 1 The structure of the device shown in the figure does not constitute a limitation of the device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0081] like Figure 1 As shown, the memory 1005 as a computer storage medium may include an operating system, a network communication module, a user interface module, and a permanent magnet synchronous motor sliding mode control program.

[0082] exist Figure 1 In the terminal shown, the network interface 1004 is mainly used to connect to the background server and communicate data with the background server; the user interface 1003 is mainly used to connect to the client (user end) and communicate data with the client; and the processor 1001 can be used to call the permanent magnet synchronous motor sliding mode control program stored in the memory 1005 and perform the following operations:

[0083] Based on the mathematical model of permanent magnet synchronous motor, the motor state equation is constructed;

[0084] Based on the mathematical model of the permanent magnet synchronous motor, the load torque is regarded as an external disturbance, and a new adaptive nonlinear extended state observer is constructed;

[0085] Based on the motor state equation, a non-singular fast terminal sliding surface and a new variable gain exponential reaching law are constructed;

[0086] Based on the novel adaptive nonlinear extended state observer, the nonsingular fast terminal sliding mode surface and the novel variable gain exponential reaching law, a novel nonsingular fast terminal sliding mode controller is constructed;

[0087] The novel non-singular fast terminal sliding mode controller is used to perform sliding mode control of a permanent magnet synchronous motor.

[0088] The specific embodiments of the present invention applied to the device are basically the same as the embodiments of the following permanent magnet synchronous motor sliding mode control method, and will not be described in detail here.

[0089] The embodiment of the present invention provides a sliding mode control method for a permanent magnet synchronous motor, referring to Figure 2 , Figure 2 It is a flow chart of an embodiment of a sliding mode control method for a permanent magnet synchronous motor of the present invention.

[0090] In this embodiment, the permanent magnet synchronous motor sliding mode control method includes the following steps:

[0091] S100: Construct the motor state equation based on the permanent magnet synchronous motor mathematical model;

[0092] S200: Based on the permanent magnet synchronous motor mathematical model, the load torque is regarded as an external disturbance, and a new adaptive nonlinear extended state observer is constructed;

[0093] S300: Based on the motor state equation, construct a non-singular fast terminal sliding mode surface and a new variable gain exponential reaching law;

[0094] S400: constructing a novel non-singular fast terminal sliding mode controller based on the novel adaptive nonlinear extended state observer, the non-singular fast terminal sliding mode surface and the novel variable gain exponential reaching law;

[0095] S500: Utilize the novel non-singular fast terminal sliding mode controller to perform sliding mode control of the permanent magnet synchronous motor.

[0096] In order to explain the present invention more clearly, the following provides a specific example of the sliding mode control method of the permanent magnet synchronous motor in practical application. Figure 3-Figure 4 As shown, the following execution steps are included:

[0097] Step 1: Establish a mathematical model of the permanent magnet synchronous motor in the dq synchronous rotating coordinate system.

[0098] The voltage equation is:

[0099] (1)

[0100] in Where: , , , are the dq axis stator voltage and stator current respectively; , , , They are dq axis stator flux and stator inductance respectively; is the stator resistance; is the permanent magnet fundamental wave excitation magnetic field chain; is the electrical angular velocity; is the polar logarithm; is the mechanical angular velocity of the rotor; is the rotation angle.

[0101] By transforming formula (1), we can get:

[0102] (2)

[0103] The torque equation and the equation of motion are:

[0104] (3)

[0105] In the formula The electromagnetic torque provided to the PMSM; is the load torque; is the friction coefficient; is the moment of inertia.

[0106] From formula (6), we get:

[0107] (4)

[0108] Surface mounted permanent magnet synchronous motor ( ) as an example, the motor model is written as:

[0109] (5)

[0110] Step 2: Design a new adaptive NESO.

[0111] In actual permanent magnet synchronous motor control, external disturbances caused by unmodeled errors, parameter changes, etc. are generally unknown. To address this issue, in order to improve the control accuracy of permanent magnet synchronous motors and accurately track the position and speed of permanent magnet synchronous motors, the load torque is regarded as an external disturbance to construct an observer. At the same time, in view of the large state tracking error and slow convergence speed of ordinary linear extended state observers and nonlinear extended state observers based on fal functions, a new type of nonlinear extended state observer is constructed:

[0112] (6)

[0113] in , , , , ; , NESO observed , The estimated value of , are the corresponding tracking errors, where the estimation error There is an upper bound, that is, there is a constant ,make .

[0114] In order to improve the adaptive ability of the observer, Replaced by the adaptive coefficient term, the new adaptive nonlinear extended state observer can be obtained as shown in formula (7):

[0115] (7)

[0116] in , , Functions such as Figure 5 shown.

[0117] Step 3: Design of a new non-singular fast terminal sliding mode controller.

[0118] The position error is defined as:

[0119] (8)

[0120] In the formula is the desired value of the PMSM position.

[0121] By taking the derivative of formula (8), we can get:

[0122] (9)

[0123] In the formula is the speed error.

[0124] From formula (5) and formula (6), we can get:

[0125] (10) In order to improve the system response speed, weaken chattering, and avoid singularity, the following non-singular fast terminal sliding surface is designed:

[0126] (11)

[0127] Where: , , ; For this sliding surface, given any , the system can asymptotically stabilize to the equilibrium state point in a finite time When the system is far away from the equilibrium point, due to the state High-order terms The existence of ensures that the system has a faster convergence speed; when the system is close to the equilibrium state point, the state The higher order terms can be ignored. It is ensured that the system can converge to the equilibrium state point asymptotically in a finite time.

[0128] Deriving equation (11) and substituting equation (10) into it, we get:

[0129] (12)

[0130] In order to improve the convergence performance of traditional sliding mode control and suppress system chattering, a new variable gain exponential reaching law is designed:

[0131] (13)

[0132] In the formula , , , , , , .in for An increasing function that satisfies ; middle and Both is a decreasing function, then for The increasing function of .

[0133] By making equation (12) equal to the reaching law (13), the controller is obtained as:

[0134] (14)

[0135] From the new adaptive NESO (10) For unknown load The estimated value of The design is applied to the controller as a compensation term to achieve feedforward compensation of the controller. Then the new non-singular fast terminal sliding mode controller is: (15)

[0136] Step 4: Analysis of system steady-state error bound and convergence time

[0137] The controller Substituting into formula (12), we get:

[0138]

[0139] (16)

[0140] Define a bounded Lyapunov function:

[0141] (17)

[0142] When the estimation error reaches a bounded constant, for:

[0143] (18)

[0144] Also know , ,make , then formula (18) can be expanded to:

[0145] (19)

[0146] Considering the steady-state error bound of the reaching law when some terms of equation (19) act alone, we can always take a sufficiently large parameter ,make ,even though , at this time:

[0147] (20)

[0148] Similarly, , and substitute formula (13) into it to obtain:

[0149] (twenty one)

[0150] 1) When When it converges to the steady-state error bound, we have If it is always established, then it is acceptable , then formula (21) can be transformed into:

[0151] (twenty two)

[0152] We can get:

[0153] (twenty three)

[0154] 2) Similarly When it converges to the steady-state error bound, take , then formula (21) can be transformed into:

[0155] (twenty four)

[0156] We can get:

[0157] (25)

[0158] At this time there are:

[0159] (26)

[0160] in: .

[0161] The above two cases only consider the partial terms of the reaching law. range, then under the action of all terms of the reaching law The following ranges will be taken:

[0162]

[0163] (27)

[0164] Assume that the system convergence time is , it is easy to see that there are always two constants , , so that

[0165]

[0166]

[0167] (28)

[0168] According to formula (28), we can get

[0169] (29)

[0170] Therefore, for any initial condition , the Lyapunov function will converge to the origin in a finite time, and the convergence time is:

[0171] (30)

[0172] in: , Represent the zero time and time At the same time, When ,and ,but . It can be obtained that

[0173] (31)

[0174] Based on the above analysis, PMSM controller It can converge to a stable state in a limited time under the action of .

[0175] In order to verify the superiority of the control method of the present invention, MATLAB / Simulink is used for simulation analysis. The parameters of the permanent magnet synchronous motor are shown in Table 1, and the parameters in the simulation are shown in Table 2.

[0176] Table 1 Permanent magnet synchronous motor parameters

[0177]

[0178] Table 2 Simulation parameters

[0179]

[0180] like Figure 6 As shown in FIG. 1 , the convergence speed comparison curve obtained by simulating the novel variable gain exponential reaching law and the common exponential reaching law of the present invention can be seen. It can be seen that when the PMSM is started without load, the load torque is Time becomes , set the expected position to , the initial position is When the sliding mode using the reaching law of the present invention is approximately When it approaches a steady state, the steady-state error is about ,

[0181] The sliding mode using the ordinary exponential reaching law is approximately When it approaches a steady state, the steady-state error is about It can be seen that the convergence law of the present invention has a faster convergence speed and reduces the steady-state error.

[0182] analyze Figure 7 and Figure 8When no observer is added, the position tracking curve and position error comparison curve are obtained by simulating the new NFTSMC of the present invention and the ordinary NFTSMC. It can be seen that when the PMSM is started without load, the load torque is Time becomes , set the expected position to , the initial position is When the novel NFTSMC of the present invention is about When it approaches a steady state, the steady-state error is about , ordinary NFTSMC is about tends to steady state, and the steady-state error is about It can be seen that the new NFTSMC of the present invention has a faster approach speed, a smaller steady-state error, and a higher control accuracy.

[0183] analyze Fig. 9 and Fig.10 The load torque is obtained by simulating the new NESO, NESO based on fal function and LESO according to the present invention. Curves and Estimation Errors By comparing the curves, it can be seen that when PMSM is started without load, the load torque is Time becomes , set the expected position to , the initial position is When the load torque estimation error of the new adaptive NESO of the present invention is about Converges to zero, and the NESO load torque estimation error based on the fal function is approximately Converges to zero, and the LESO load torque estimation error is approximately Converges to zero; the new adaptive NESO peak speed estimation error of the present invention is approximately The error of NESO peak speed estimation based on the fal function is approximately , the LESO peak speed estimation error is approximately It can be seen that the NESO of the present invention has a stronger suppression ability for external load interference and can significantly improve the steady-state accuracy of the controlled object.

[0184] analyze Fig.11 The position tracking curves are obtained by simulating the new NFTSMC control strategy of the present invention and the common NFTSMC control strategy. It can be seen that when the PMSM is started without load, the load torque is Time becomes , given step position , the initial position is When the novel NFTSMC of the present invention is about Arrived at the designated location, the normal NFTSMC is about When the specified position is reached, it can be seen that the new NFTSMC control strategy of the present invention has a faster convergence speed.

[0185] analyze Fig.12 and Fig.13 The position tracking curve and position error comparison curve are obtained by simulating the new NFTSMC control strategy of the present invention and the common NFTSMC control strategy. It can be seen that when the PMSM is started without load, the load torque is Time becomes , set the expected position to , the initial position is When the position error of the new NFTSMC of the present invention is about Converges to zero, the position error of ordinary NFTSMC is about It converges to zero, which shows that the novel NFTSMC control strategy of the present invention has a faster approaching speed.

[0186] Table 3 shows the convergence time based on different schemes and the percentage reduction of the convergence time of the present invention. , As given in formula (32), is the convergence time of the solution of the present invention, Table 4 shows the convergence error of different solutions and the percentage of error reduction of the present invention. , As given in formula (33), This is the error of the present invention. is the comparison scheme error.

[0187] (32)

[0188] (33)

[0189] Table 3 Convergence time and percentage reduction of convergence time of the present invention

[0190]

[0191] Table 4 Convergence error and error reduction percentage of the present invention

[0192]

[0193] It can be concluded from Tables 3 and 4 that under different conditions, the control method of the present invention can minimize the tracking error of the permanent magnet synchronous motor, and it is significantly reduced compared with the comparison scheme; at the same time, the control method of the present invention has the shortest convergence time and has a good response speed.

[0194] Therefore, the present invention aims at the problems that the traditional PI control strategy of permanent magnet synchronous motor is difficult to eliminate the influence of external disturbances, and the traditional sliding mode control is prone to produce large jitter and cannot converge in a finite time. The present invention proposes a composite control strategy combining a new adaptive NESO and a non-singular terminal sliding mode control. The designed controller greatly weakens the jitter, avoids singularity, and enables the system to converge to the equilibrium point asymptotically in a finite time. At the same time, the new variable gain exponential reaching law designed in the controller reduces the jitter of the system while improving the approach speed compared to the ordinary exponential reaching law; the new adaptive NESO proposed for the first time not only greatly reduces the deviation of the estimation error compared to the ordinary LESO and the NESO based on the ordinary fal function, but also significantly improves the approach speed.

[0195] like Fig.14 As shown, the sliding mode control device of a permanent magnet synchronous motor proposed in an embodiment of the present invention includes:

[0196] The first construction module 10 is used to construct a motor state equation based on a permanent magnet synchronous motor mathematical model;

[0197] The second construction module 20 is used to construct a novel adaptive nonlinear extended state observer based on the permanent magnet synchronous motor mathematical model and regard the load torque as an external disturbance;

[0198] A third construction module 30 is used to construct a non-singular fast terminal sliding mode surface and a novel variable gain exponential reaching law based on the motor state equation;

[0199] A fourth construction module 40 is used to construct a novel non-singular fast terminal sliding mode controller based on the novel adaptive nonlinear extended state observer, the non-singular fast terminal sliding mode surface and the novel variable gain exponential reaching law;

[0200] The control module 50 is used to perform sliding mode control of the permanent magnet synchronous motor using the novel non-singular fast terminal sliding mode controller.

[0201] Other embodiments or specific implementations of the sliding mode control device for a permanent magnet synchronous motor of the present invention may refer to the above-mentioned method embodiments and will not be described in detail here.

[0202] In addition, the present invention also proposes a permanent magnet synchronous motor sliding mode control device, which includes: a memory, a processor, and a permanent magnet synchronous motor sliding mode control program stored in the memory and executable on the processor. When the permanent magnet synchronous motor sliding mode control program is executed by the processor, the steps of the permanent magnet synchronous motor sliding mode control method as described above are implemented.

[0203] The specific implementation of the permanent magnet synchronous motor sliding mode control device of the present application is basically the same as the embodiments of the permanent magnet synchronous motor sliding mode control method described above, and will not be repeated here.

[0204] In addition, the present invention also proposes a readable storage medium, the readable storage medium includes a computer readable storage medium, on which a permanent magnet synchronous motor sliding mode control program is stored. The readable storage medium may be Figure 1 The memory 1005 in the terminal may also be at least one of a ROM (Read-Only Memory) / RAM (Random Access Memory), a magnetic disk, and an optical disk. The readable storage medium includes a number of instructions for enabling a permanent magnet synchronous motor sliding mode control device having a processor to execute the permanent magnet synchronous motor sliding mode control method described in each embodiment of the present invention.

[0205] The specific implementation methods in the readable storage medium of the present application are basically the same as the above-mentioned embodiments of the sliding mode control method of the permanent magnet synchronous motor, and will not be repeated here.

[0206] It is understood that, in the description of this specification, the description with reference to the terms "one embodiment", "another embodiment", "other embodiments", or "first to Nth embodiments" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0207] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0208] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0209] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for a terminal device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0210] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A sliding mode control method for a permanent magnet synchronous motor, characterized in that: The following steps are involved: Based on the mathematical model of permanent magnet synchronous motor, the motor state equation is constructed; Based on the mathematical model of the permanent magnet synchronous motor, the load torque is regarded as an external disturbance, and a new adaptive nonlinear extended state observer is constructed; Based on the motor state equation, a non-singular fast terminal sliding surface and a new variable gain exponential reaching law are constructed; Based on the novel adaptive nonlinear extended state observer, the nonsingular fast terminal sliding mode surface and the novel variable gain exponential reaching law, a novel nonsingular fast terminal sliding mode controller is constructed; Using the novel non-singular fast terminal sliding mode controller to perform sliding mode control of a permanent magnet synchronous motor; Among them, based on the mathematical model of permanent magnet synchronous motor, the motor state equation is constructed, including: Establishing voltage equations, torque equations and motion equations of the dq-axis stator and rotor, combining the deformed expression of the voltage equation with the torque equation and the motion equation, and establishing a mathematical model of the permanent magnet synchronous motor with the constraint that the d-axis stator flux is equal to the q-axis stator flux; The expression of the mathematical model of the permanent magnet synchronous motor is specifically: Where ω is the mechanical angular velocity of the rotor, n p is the polar logarithm, ψ f is the permanent magnet fundamental excitation magnetic field chain, i q is the q-axis stator current, B is the friction coefficient, T l is the load torque, J is the moment of inertia, and the d-axis stator flux is constrained to be equal to the q-axis stator flux, specifically: L d =L q =L s ; Based on the mathematical model of permanent magnet synchronous motor, the motor state equation is constructed; The expression of the motor state variable of the motor state equation is specifically: e θ =θ-θ r In the formula, θ r is the expected value of the permanent magnet synchronous motor position; Among them, based on the permanent magnet synchronous motor mathematical model, the load torque is regarded as an external disturbance, and a new adaptive nonlinear extended state observer is constructed, which specifically includes: The load torque is regarded as an external disturbance, a new nonlinear extended state observer is constructed, the coefficient λ2 in the new nonlinear extended state observer is replaced by an adaptive coefficient, and the new nonlinear extended state observer is updated to obtain a new adaptive nonlinear extended state observer; Among them, the expression of the new nonlinear extended state observer is: In the formula, a>0, b>0, λ1>0, λ2>0, 0<β<1; are ω and T observed by NESO respectively. l The estimated values ​​of e1, e d is the tracking error, where the estimation error e d There is an upper bound, that is, there is a constant υ such that e d ≤v; Among them, the expression of the updated new adaptive nonlinear extended state observer is: In the formula, α>0, 0<μ<1.

2. The sliding mode control method of a permanent magnet synchronous motor according to claim 1, characterized in that: Based on the motor state equation, a non-singular fast terminal sliding surface and a new variable gain exponential reaching law are constructed, specifically including: Based on the set permanent magnet synchronous motor state variables, a non-singular fast terminal sliding surface and a new variable gain exponential reaching law are designed; The expression of the non-singular fast terminal sliding surface is specifically: In the formula, θ r is the expected value of the permanent magnet synchronous motor position, k1>0, k2>0, k3>0; 1 <a2<a1<2; The expression of the novel variable gain exponential reaching law is specifically: In the formula, c>0, η>0, ε>0, p>0, q>0, l>0, K(σ) is an increasing function of |σ| and satisfies f(v) in (|σ|+1) -l With pe -q|σ| are all decreasing functions of |σ|, then f(σ) is an increasing function of |σ|.

3. The sliding mode control method of a permanent magnet synchronous motor according to claim 2, characterized in that: Based on the novel adaptive nonlinear extended state observer, the non-singular fast terminal sliding mode surface and the novel variable gain exponential reaching law, a novel non-singular fast terminal sliding mode controller is constructed, which specifically includes: Making the expression of the derivative of the non-singular fast terminal sliding mode surface equal to the expression of the novel variable gain exponential reaching law, to obtain an initial novel non-singular fast terminal sliding mode controller; Among them, the non-singular fast terminal sliding surface derivative expression is specifically: Among them, the expression of the initial new non-singular fast terminal sliding mode controller is: The load torque is estimated by using the novel adaptive nonlinear extended state observer, and the obtained load estimation value is added as a compensation term to the initial novel non-singular fast terminal sliding mode controller to obtain a final novel non-singular fast terminal sliding mode controller; Among them, the final expression of the new non-singular fast terminal sliding mode controller is: Where, T l is the load torque, is the estimated value of load torque.

4. The sliding mode control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The steps of performing the sliding mode control of the permanent magnet synchronous motor by using the novel non-singular fast terminal sliding mode controller specifically include: The steady-state error bound and convergence time of the generated novel non-singular fast terminal sliding mode controller are analyzed to determine whether the permanent magnet synchronous motor can converge to a stable state within a finite time under the action of the novel non-singular fast terminal sliding mode controller; If so, the finally obtained novel non-singular fast terminal sliding mode controller is used as the permanent magnet synchronous motor sliding mode control execution.

5. A sliding mode control device for a permanent magnet synchronous motor, characterized in that: include: The first building module is used to build a motor state equation based on a permanent magnet synchronous motor mathematical model; The second building module is used to construct a novel adaptive nonlinear extended state observer based on the permanent magnet synchronous motor mathematical model and regard the load torque as an external disturbance; A third building module is used to construct a non-singular fast terminal sliding surface and a novel variable gain exponential reaching law based on the motor state equation; A fourth building block is used to build a novel non-singular fast terminal sliding mode controller based on the novel adaptive nonlinear extended state observer, the non-singular fast terminal sliding mode surface and the novel variable gain exponential reaching law; A control module, used for performing sliding mode control of a permanent magnet synchronous motor using the novel non-singular fast terminal sliding mode controller; Among them, based on the mathematical model of permanent magnet synchronous motor, the motor state equation is constructed, including: Establishing voltage equations, torque equations and motion equations of the dq-axis stator and rotor, combining the deformed expression of the voltage equation with the torque equation and the motion equation, and establishing a mathematical model of the permanent magnet synchronous motor with the constraint that the d-axis stator flux is equal to the q-axis stator flux; The expression of the mathematical model of the permanent magnet synchronous motor is specifically: Where ω is the mechanical angular velocity of the rotor, n p is the polar logarithm, ψ f is the permanent magnet fundamental excitation magnetic field chain, i q is the q-axis stator current, B is the friction coefficient, T l is the load torque, J is the moment of inertia, and the d-axis stator flux is constrained to be equal to the q-axis stator flux, specifically: L d =L q =L s ; Based on the mathematical model of permanent magnet synchronous motor, the motor state equation is constructed; The expression of the motor state variable of the motor state equation is specifically: e θ =θ-θ r In the formula, θ r is the expected value of the permanent magnet synchronous motor position; Among them, based on the permanent magnet synchronous motor mathematical model, the load torque is regarded as an external disturbance, and a new adaptive nonlinear extended state observer is constructed, which specifically includes: The load torque is regarded as an external disturbance, a new nonlinear extended state observer is constructed, the coefficient λ2 in the new nonlinear extended state observer is replaced by an adaptive coefficient, and the new nonlinear extended state observer is updated to obtain a new adaptive nonlinear extended state observer; Among them, the expression of the new nonlinear extended state observer is: In the formula, a>0, b>0, λ1>0, λ2>0, 0<β<1; are ω and T observed by NESO respectively. l The estimated values ​​of e1, e d is the tracking error, where the estimation error e d There is an upper bound, that is, there is a constant ν such that e d ≤ν; Among them, the expression of the updated new adaptive nonlinear extended state observer is: In the formula, α>0, 0<μ<1.

6. A permanent magnet synchronous motor sliding mode control device, characterized in that: The permanent magnet synchronous motor sliding mode control device comprises: a memory, a processor and a permanent magnet synchronous motor sliding mode control program stored in the memory and executable on the processor. When the permanent magnet synchronous motor sliding mode control program is executed by the processor, the steps of the permanent magnet synchronous motor sliding mode control method as described in any one of claims 1 to 4 are implemented.

7. A storage medium, characterized in that: The storage medium stores a permanent magnet synchronous motor sliding mode control program, and when the permanent magnet synchronous motor sliding mode control program is executed by the processor, the steps of the permanent magnet synchronous motor sliding mode control method according to any one of claims 1 to 4 are implemented.

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