Permanent magnet synchronous motor sliding mode control method and system based on disturbance compensation

Abstract

The invention provides a permanent magnet synchronous motor sliding mode control method and system based on disturbance compensation, and the method comprises the steps: constructing a first motor state equation based on a permanent magnet synchronous motor mathematical model containing disturbance; secondly, on the basis of a sliding mode control theory, a novel adaptive reaching law and a non-singular fast terminal sliding mode surface are constructed, stability proving is completed, and the fast convergence capability is analyzed; designing a novel speed ring controller through the state equation, the reaching law and the sliding mode surface; designing a sliding mode disturbance observer for a disturbance part in the speed loop controller; and finally, carrying out FOC speed regulation control on the permanent magnet synchronous motor by using the designed speed ring controller and the disturbance observer. Compared with an existing well-known sliding mode control scheme, the hybrid control method of the speed loop controller and the sliding mode disturbance observer is adopted, system buffeting is effectively weakened, meanwhile, the dynamic response speed is considered, and the system robustness is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of permanent magnet synchronous motor control, in particular to a permanent magnet synchronous motor sliding mode control method and system based on disturbance compensation. BACKGROUND

[0002] Permanent magnet synchronous motor (PMSM) has been widely used in industrial drives, electric vehicles and household appliances due to its high efficiency, high power density and good dynamic performance. However, the control strategy of PMSM is complex, especially in the case of load disturbance and parameter variation, the traditional control method such as PI speed loop regulation will be difficult to meet the requirements of high performance control.

[0003] Sliding mode control (SMC) has become an important research direction for high performance control of PMSM due to its natural robustness to matching uncertainty and external disturbance and fast error convergence ability. By constructing a suitable sliding surface and designing a reaching law, the system state is forced to approach and remain near the desired trajectory in a finite time, so that good tracking and stability are maintained under load mutation, parameter drift and noise disturbance. However, because of the discontinuity of the system and the switching term in the traditional exponential sliding mode reaching law, the sliding mode control will have chattering phenomenon. In order to weaken the chattering, the reaching rate gain coefficient is often reduced, but it will increase the time of motion point reaching the sliding surface. Some people have proposed the idea of terminal sliding mode control, which uses a nonlinear function to construct a sliding surface, so that the error converges in a finite time. However, if the sliding surface parameters are not properly selected, the system will appear "singular" phenomenon, which seriously affects the performance of the system. SUMMARY

[0004] In order to solve the problem that the existing technology cannot balance the suppression of chattering phenomenon and convergence time in sliding film control, the present application provides a permanent magnet synchronous motor sliding mode control system based on disturbance compensation, which includes a permanent magnet synchronous motor, a sensor, a current sampling unit, a sliding mode disturbance observer, a speed loop controller, a PI current loop controller, an SVPWM module, an inverter and a coordinate transformation module. The current sampling unit collects three-phase current signals abc , , and output by the inverter in three-phase stationary coordinate system. , , αβ , i α and i β , i α and​i β Park transformation dq Two-phase current in two-phase rotating coordinate system i d And i q ; The sliding mode disturbance observer calculates the rotor position of the permanent magnet synchronous motor and the rotor mechanical angular velocity and the rotor mechanical angular velocity The disturbance value that needs to be compensated is calculated and the disturbance observation value is output ; According to the error of the speed expectation value and the rotor mechanical angular velocity , the disturbance observation value , the speed loop controller outputs q the d-axis current expectation value ; According to the input i q and , the PI current loop controller outputs q the d-axis voltage expectation value ; According to the input i d and d the d-axis current expectation value i dref =0, the PI current loop controller outputs d the d-axis current expectation value ; and After the coordinate transformation module, the two-phase voltage in the two-phase stationary coordinate system is obtained αβ u αref and u βref The input SVPWM module converts the target synthesized voltage vector into a control signal for the inverter, and the rotating voltage vector output by the inverter drives the permanent magnet synchronous motor to operate.

[0005] The application also provides a sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation, and the control system is realized, comprising the following steps: Step one: based on the mathematical model of the permanent magnet synchronous motor containing disturbance, the first motor state equation is established by taking the speed error as the state variable; Step two: based on the sliding mode control theory, the adaptive approach law and the non-singular fast terminal sliding surface are constructed; Step three: according to the first motor state equation in step one, the adaptive approach law and the non-singular fast terminal sliding surface in step two, the speed loop controller is designed; Step four: the sliding mode disturbance observer is designed for the disturbance part in the speed loop controller;​ Step five: FOC speed control of permanent magnet synchronous motor using the speed loop controller and sliding mode disturbance observer: according to the disturbance observation value output by the sliding film disturbance observer, the error of the rotor mechanical angular velocity and the speed loop controller output current expected value; two-phase voltage obtained through the PI current loop controller and the coordinate transformation module u αref and u βref input SVPWM module, SVPWM module converts target synthesized voltage vector into control signal for inverter; rotating voltage vector output by inverter drives permanent magnet synchronous motor to run.

[0006] Further, the specific construction process of the first motor state equation in step one is as follows: The mathematical model of permanent magnet synchronous motor in the shaft rotating coordinate system includes voltage equation, electromagnetic torque equation and mechanical motion equation, and the expressions of each equation are as follows: The voltage equation is:

[0007] In the formula, , are the voltages of the d axis and the q axis respectively; , are the currents of the d axis and the q axis respectively; , are the inductances of the d axis and the q axis respectively; is the stator resistance; The electromagnetic torque equation is as follows:

[0008] The mechanical motion equation is as follows:

[0009] Based on the permanent magnet synchronous motor mathematical model containing disturbance, the first motor state equation is established with the speed error as the state variable:

[0010] In the formula, is the system state variable, is the speed expected value.

[0011] Further, for the surface-mounted three-phase permanent magnet synchronous motor, it satisfies where Ls is the inductance of the stator.​

[0012] Furthermore, the adaptive reaching law in step two is:

[0013] In the formula, ; e It is a natural constant; The coefficients are the adaptive term coefficients, and sigmoid(·) is the function symbol; It is the linear amplification factor. It is a correction factor for the index. It is the coefficient of the exponential term. It is the coefficient of the power term. It is the linear amplification factor of the power term. This is a coefficient used to control the rate of change of the synovial surface index; Non-singular fast terminal sliding surface s The expression is:

[0014] In the formula, , , , It is a positive odd number, and , .

[0015] Furthermore, the speed loop controller expression in step two is:

[0016] In the formula, i qref for q Desired value of shaft current For rotational inertia, e 1 represents the system state variable. The rotor's mechanical angular velocity, It is a permanent magnet flux chain. is the coefficient of viscous friction.

[0017] Furthermore, the design process of the sliding mode perturbation observer in step four is as follows: Based on the rotor mechanical angular velocity and disturbance Establish the state equations for the second motor:

[0018] The sliding mode disturbance observer equations are established by observing the rotor's mechanical angular velocity and disturbances:

[0019] In the formula , For observer gain, For perturbation sliding mode gain, For electromagnetic torque, These are observed values ​​of mechanical angular velocity. These are perturbation observations.

[0020] Furthermore, in step two The function is: .

[0021] Furthermore, the FOC speed control method for the permanent magnet synchronous motor in step five is as follows: Step S1: Collect the rotor position of the permanent magnet synchronous motor using sensors. Rotor angular velocity Three-phase current signals are acquired through a current sampling unit. , and ; Step S2: The sliding mode disturbance observer measures the rotor's mechanical angular velocity and rotational speed. The coordinate transformation module is used to obtain the three-phase current signal. The axis current is used to calculate the disturbance value that needs to be compensated and output the disturbance observation value. ; Step S3: The speed loop controller determines the desired rotational speed. Compared with the actual rotor mechanical angular velocity Errors and disturbances in observed values Update the output of the speed loop controller ; Step S4: The PI current loop controller, based on the given... Track the expected value of the shaft current and output. Desired value of shaft voltage , ; Step S5: For The shaft voltage undergoes Park inverse transformation and is input into the SVPWM module to complete the phase current regulation of the three-phase full-bridge inverter. Then, the inverter outputs control signals to drive the PMSM to operate. Repeat steps S1 to S5 to continuously provide feedback on the expected rotational speed. Compared with the actual rotor mechanical angular velocity To reduce errors and achieve speed control.

[0022] Compared with the prior art, this invention has the following beneficial effects: This invention, compared to existing permanent magnet synchronous motor sliding mode control, designs an adaptive reaching law based on the traditional exponential reaching law, by using... Functions replace traditional Switching functions and related system state variables The adaptive term coefficients reduce system chattering while ensuring that the tracking error converges within a finite time. At the same time, a non-singular fast terminal sliding surface is introduced on the basis of the traditional linear sliding surface to achieve the best convergence speed at different stages, thus ensuring the global fastness of the convergence speed.

[0023] The sliding mode disturbance observer proposed in this invention can quickly estimate the load disturbance applied to the system and feed the estimation result forward to the speed controller, avoiding the use of large switching gain, thereby reducing motor speed jitter and improving the disturbance immunity of the motor speed control system. Attached Figure Description

[0024] Figure 1 This is a flowchart of a method according to an embodiment of the present invention; Figure 2 This is a system block diagram of the dual closed-loop vector control of a permanent magnet synchronous motor according to an embodiment of the present invention; Figure 3 This is a block diagram of the internal structure of the sliding mode speed loop controller according to an embodiment of the present invention; Figure 4 This is a block diagram of the internal structure of the disturbance observer according to an embodiment of the present invention; Figure 5 This is a comparison chart of the estimated disturbance and the actual disturbance tracking by a sliding mode disturbance observer according to an embodiment of the present invention; Figure 6 This is a comparison chart of the rotational speed response of the strategy in this embodiment of the invention and that of traditional sliding mode control; Figure 7 The strategy of this invention embodiment and traditional sliding mode control q Comparison of shaft current response; Figure 8 The strategy of this invention embodiment and traditional sliding mode control d Comparison of shaft current response. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. The terms "upper," "lower," "front," "rear," "top," "bottom," etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or part referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0027] like Figure 2 As shown, a sliding mode control system for a permanent magnet synchronous motor based on disturbance compensation includes a permanent magnet synchronous motor (PMSM), a Velocity Position Sensor, a current sampling unit, a Sliding Mode Disturbance Observer (SMDOB), a speed loop controller (NSTSMC), a PI current loop controller, an SVPWM module (Space Vector Pulse Width Modulation), an inverter, and a coordinate transformation module; wherein the coordinate transformation module includes... Three-phase stationary coordinate system Two-phase stationary coordinate system and The mutual transformation between two rotating coordinate systems. In this embodiment, the sensor uses a rotary transformer.

[0028] The current sampling unit collects the inverter output. abc Three-phase current signal in a three-phase stationary coordinate system , and The coordinate transformation module uses Clark transformation to transform the three-phase current signals. , and Convert to αβ Two-phase stationary coordinate system i α and i β , i α and i β Obtained through Park transformation dq Two-phase current in a two-phase rotating coordinate system i d and i q ; The sliding mode disturbance observer uses the rotor position of the permanent magnet synchronous motor acquired by the sensor. and rotor mechanical angular velocity Calculate the disturbance value that needs to be compensated and output the disturbance observation value. Based on the desired rotational speed With rotor mechanical angular velocity Errors and disturbances in observed values Speed ​​loop controller output q Desired value of shaft current According to the input i q and PI current loop controller output q Desired value of shaft voltage According to the input i d and d Desired value of shaft current i dref =0, PI current loop controller output d Desired value of shaft current ; and After coordinate transformation module, the result is obtained αβ Two-phase voltage in a two-phase stationary coordinate system u αref and u βref The input is to the SVPWM module, which converts the target synthesized voltage vector into a control signal for the inverter. The rotating voltage vector output by the inverter drives the permanent magnet synchronous motor to operate.

[0029] like Figure 1 As shown in the figure, this embodiment discloses a sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation, including the following steps: Step 1: Based on the mathematical model of the permanent magnet synchronous motor with disturbance, construct the first motor state equation.

[0030] Permanent magnet synchronous motor in The mathematical model in the rotating coordinate system includes the voltage equation, the electromagnetic torque equation, and the mechanical motion equation. The expressions for each equation are as follows: The voltage equation is: (1) In the formula, , They are respectively d shaft and q shaft voltage, , They are respectively d shaft and q shaft current, , They are respectively d shaft and q Shaft inductor, For stator resistance, The rotor's mechanical angular velocity, It is a permanent magnet flux chain. This represents the number of pole pairs of the motor.

[0031] For surface-mounted three-phase permanent magnet synchronous motors, the following requirements must be met. ,in L s The inductance is for the stator.

[0032] The electromagnetic torque equation is as follows: (2) In the formula, It is electromagnetic torque.

[0033] The equations of motion for the machine are as follows: (3) In the formula, For rotational inertia, T L For load torque, It is the coefficient of viscous friction; In motor speed control systems, the externally applied load torque is typically used as the input torque. Consider it a disturbance. Then equation (3) can be transformed into: (4) Based on the mathematical model of a permanent magnet synchronous motor with disturbances, the first motor state equation is established with speed error as the state variable: (5) In the formula, For system state variables, i.e., speed error, This represents the desired rotational speed.

[0034] Step 2: Based on sliding mode control theory, construct an adaptive reaching law and a non-singular fast terminal sliding surface, complete the stability proof, and analyze its fast convergence capability.

[0035] Regarding the traditional exponential approach law Analysis shows that when the system is far from the sliding surface, the approach velocity is mainly determined by the coefficient of the exponential term. And this is determined by the constant velocity coefficient when the system approaches the sliding surface; It works. To increase the system's approach speed, the [capacity] must be increased. and However, this will cause the system to experience greater jitter.

[0036] Due to the sign function in the control law It is a piecewise function, and frequent switching is the main cause of system chattering. The larger the size, the greater the corresponding chattering. The function is a continuous function, therefore, we use... Functions replace symbolic functions in sliding mode control To achieve precise sliding control, system chattering can be effectively reduced.

[0037] The adaptive reaching law proposed in this invention is as follows: (6) in The function is: (7) In the formula, , e It is a natural constant.

[0038] s It is a sliding surface function, and its reaching law includes an exponential term. Adaptive constant velocity term k e sigmoid(s) composition. The coefficients of the adaptive term are derived from the power term. and nonlinear compensation terms composition.

[0039] The nonlinear compensation term is determined by the exponent of the synovial surface. To adjust, Used to control the rate of change of the synovial surface index. It is the linear amplification factor. It is a correction factor for the index. It is the coefficient of the exponential term. It is the coefficient of the power term. It is the linear amplification factor of the power term.

[0040] Therefore, when the system is far from the sliding surface, the approach law holds true. The value is approximately Its value is much greater than In other words, the adaptive isotropic term significantly accelerates the approach speed compared to the fixed isotropic term in the traditional approach law, ensuring a shorter approach time and stronger robustness of the system. When the system approaches the sliding surface, under the influence of the power term and the nonlinear compensation term, The value will decrease significantly, which can effectively suppress system chattering.

[0041] Proof of the stability of the adaptive reaching law, defining the Lyapunov function. ,for Differentiation yields: (8) because , ,Right now Established.

[0042] For commonly used linear sliding surfaces ( ) and integral sliding surface ( , The analysis focuses on the drawbacks of linear sliding surfaces, including slow convergence when the system state variables are close to the equilibrium position of the sliding surface, and poor control performance for systems with complex models and high dynamic performance requirements. Integral sliding surfaces, due to the introduction of integrals, can lead to a reduction in the order of the sliding mode control system, potentially causing overshoot or saturation of the drive mechanism.

[0043] Therefore, the design concept of nonlinear sliding surfaces is adopted to improve the performance of the sliding mode control system. The general expression of a nonlinear sliding surface is as follows:

[0044] By using nonlinear sliding surfaces, and provided the parameters and nonlinear functions are chosen appropriately, the performance of sliding mode control systems can be effectively improved. This not only allows system errors to converge within a finite time but can also reduce chattering to some extent.

[0045] This invention proposes a non-singular fast terminal sliding surface as follows: (9) In the formula, , , , It is a positive odd number, and , ; when At that time, it can be known that the rate of change of the rotational speed error is: (10) When the rotational speed error converges towards the sliding surface, the convergence rate of the error depends on the exponential term, i.e. When the rotational speed error reaches the sliding surface and converges along the sliding surface to the equilibrium point, the convergence rate of the error mainly depends on the linear term, i.e. The combination of these two methods ensures rapid error convergence at different stages.

[0046] Step 3: Design a speed loop controller based on the first motor state equation (Equation (5)) in Step 1, the adaptive approach law (Equation (6)) in Step 2, and the non-singular fast terminal sliding surface (Equation (9)).

[0047] The expression for the designed speed loop controller is: (11) In the formula, i qref for q Desired value of shaft current.

[0048] The above speed loop controller structure diagram is as follows: Figure 3 As shown.

[0049] Step 4: Design a sliding mode disturbance observer for the disturbance part of the velocity loop controller.

[0050] The design of the sluice panel disturbance observer is based on the mechanical angular velocity of the rotor. and disturbance The state equation for the second motor is established as follows: (12) By observing the mechanical angular velocity and disturbance, the equations for the sliding mode disturbance observer are established as follows: (13) In the formula , For observer gain, For perturbation sliding mode gain, These are observed values ​​of mechanical angular velocity. These are perturbation observations.

[0051] The above-mentioned sliding mode disturbance observer structure diagram is as follows: Figure 4 As shown.

[0052] Subtracting equation (12) from equation (13) yields: (14) In the formula, , ; For mechanical angular velocity observation error, To account for the perturbation observation error, and select The sliding surface of the sliding mode disturbance observer.

[0053] Proof of stability of sliding mode perturbation observer, defining Lyapunov function ,for Differentiation yields: (15) Substituting equation (14) into equation (15), we get: (16) when hour, ,Pick ,but: (17) The condition for satisfying equation (17) is .

[0054] when hour, ,Pick ,but: (18) The condition for satisfying equation (18) is .

[0055] Considering both of the above situations, we can obtain the following: The constraints are:

[0056] exist When the stability condition is met, the sliding mode observer will reach the sliding mode, which can be mathematically described as follows: Combining equation (14), we can obtain the following relationship: (19) (20) In Equation (19) This relationship has the following characteristics: (twenty one) Solving the above equation, we get: (twenty two) According to the information given in equation (22) above, the created sliding mode disturbance observer has the characteristics of first-order filtering, which can filter out the erroneous observation values ​​obtained by the observer.

[0057] Step 5: Use the designed speed loop controller and sliding mode disturbance observer to perform FOC speed control of the permanent magnet synchronous motor.

[0058] The FOC speed control method for permanent magnet synchronous motors is as follows: Step S1: Acquire the rotor position of the permanent magnet synchronous motor using a sensor (rotor transformer). Rotor mechanical angular velocity Three-phase current signals are acquired through a current sampling unit (such as a sampling resistor). , and ; Step S2: The sliding mode disturbance observer measures the rotor's mechanical angular velocity and rotational speed. The three-phase current signal is obtained by Clark and Park transformation. The shaft current is calculated according to equations (4) and (13), and the disturbance observation value is output. ; Step S3: The speed loop controller determines the desired rotational speed. Compared with the actual rotor mechanical angular velocity Errors and disturbances in observed values The output of the speed loop controller is updated according to equation (11). ; Step S4: The PI current loop controller, based on the given... Track the expected value of the shaft current and output. Desired value of shaft voltage , ; Specifically, based on the input i q and PI current loop controller output q Desired value of shaft voltage According to the input i d and d Desired value of shaft current i dref (The typical control strategy is) i dref =0), PI current loop controller output d Desired value of shaft current .

[0059] Step S5: For Shaft Desired Voltage , Perform the inverse Park transform to obtain , The input is fed into the SVPWM module to complete the phase current regulation of the three-phase full-bridge inverter, and then the inverter outputs control signals to drive the PMSM to operate. Repeat steps S1 to S5 to continuously provide feedback on the expected rotational speed. Compared with the actual rotor mechanical angular velocity To reduce errors and achieve speed control.

[0060] Using the above technical solution, this invention proposes a sliding mode control method for permanent magnet synchronous motors based on disturbance compensation. It mainly designs a non-singular fast terminal sliding mode speed controller (NSTSMC) and a sliding mode disturbance observer (SMDOB). The combination of the two has excellent dynamic performance.

[0061] To verify the technical effects of the present invention, corresponding simulation experiments were conducted, based on... Figure 2The system block diagram was used to build a simulation model in Simulink. The parameters of the selected permanent magnet synchronous motor are shown in Table 1.

[0062] Table 1 Parameters of Permanent Magnet Synchronous Motor

[0063] The experimental conditions were: the motor was started under no-load, the desired speed was 1000 r / min, and at 0.2 seconds, the speed was suddenly increased by 10 r / min. The load.

[0064] See simulation results Figures 5 to 8 .

[0065] Combination Figure 5 It can be observed that the sliding mode disturbance observer converges very quickly and can capture changes in load disturbances very accurately.

[0066] Combination Figure 6 In terms of speed control, the control strategy (NSTSMC+SMDOB) proposed in this invention exhibits excellent dynamic performance, with the speed response time shortened to 0.02 seconds and no overshoot, indicating that its speed response dynamic performance is significantly better than other methods (traditional SMC and traditional PI control methods). Under the condition of sudden load increase, the speed fluctuation amplitude is extremely small and can quickly recover to the set value.

[0067] Combination Figure 7 and Figure 8 The control strategy (NSTSMC+SMDOB) proposed in this invention exhibits significant current stability during speed changes, with current fluctuations significantly smaller than those of the traditional SMC. This demonstrates that the improved SMC can effectively suppress current changes and torque fluctuations during dynamic processes, exhibiting stronger dynamic stability and anti-interference capabilities, further verifying its robustness and superior performance under complex operating conditions.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the technical principles of the present invention, and all such improvements and modifications should be covered within the protection scope of the present invention.

Claims

1. A sliding mode control system for a permanent magnet synchronous motor based on disturbance compensation, characterized in that, It includes a permanent magnet synchronous motor, sensors, current sampling unit, sliding mode disturbance observer, speed loop controller, PI current loop controller, SVPWM module, inverter, and coordinate transformation module; The current sampling unit collects the inverter output. abc Three-phase current signal in a three-phase stationary coordinate system , and The coordinate transformation module uses Clark transformation to transform the three-phase current signals. , and Convert to αβ Two-phase stationary coordinate system i α and i β , i α and i β Obtained through Park transformation dq Two-phase current in a two-phase rotating coordinate system i d and i q ; The sliding mode disturbance observer uses the rotor position of the permanent magnet synchronous motor acquired by the sensor. and rotor mechanical angular velocity Calculate the disturbance value that needs to be compensated and output the disturbance observation value. Based on the desired rotational speed With rotor mechanical angular velocity Errors and disturbances in observed values Speed ​​loop controller output q Desired value of shaft current According to the input i q and PI current loop controller output q Desired value of shaft voltage According to the input i d and d Desired value of shaft current i dref =0, PI current loop controller output d Desired value of shaft current ; and After coordinate transformation module, the result is obtained αβ Two-phase voltage in a two-phase stationary coordinate system u αref and u βref The input is to the SVPWM module, which converts the target synthesized voltage vector into a control signal for the inverter. The rotating voltage vector output by the inverter drives the permanent magnet synchronous motor to operate.

2. A sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation, implemented based on the control system described in claim 1, characterized in that, Includes the following steps: Step 1: Based on the mathematical model of the permanent magnet synchronous motor with disturbance, establish the first motor state equation with speed error as the state variable; Step 2: Based on sliding mode control theory, construct an adaptive reaching law and a non-singular fast terminal sliding surface; Step 3: Design a speed loop controller based on the first motor state equation in Step 1, the adaptive reaching law in Step 2, and the non-singular fast terminal sliding surface. Step 4: Design a sliding mode disturbance observer for the disturbance component in the velocity loop controller; Step 5: Perform FOC speed control of the permanent magnet synchronous motor using the speed loop controller and sliding mode disturbance observer: based on the disturbance observation value and the desired speed value output by the sliding mode disturbance observer. With rotor mechanical angular velocity The error, the expected value of the speed loop controller output current; Two-phase voltage obtained by PI current loop controller and coordinate transformation module u αref and u βref The input is to the SVPWM module, which converts the target synthesized voltage vector into a control signal for the inverter; the rotating voltage vector output by the inverter drives the permanent magnet synchronous motor to operate.

3. The sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation according to claim 2, characterized in that, The specific process of constructing the state equation of the first motor in step one is as follows: The mathematical model of a permanent magnet synchronous motor in a rotating axis coordinate system includes voltage equations, electromagnetic torque equations, and mechanical motion equations. The expressions for each equation are as follows: The voltage equation is: In the formula, , They are respectively d shaft and q Shaft voltage; , They are respectively d shaft and q shaft current; , They are respectively d shaft and q Shaft inductance; Stator resistance; The electromagnetic torque equation is as follows: The equations of motion for the machine are as follows: Based on the mathematical model of a permanent magnet synchronous motor with disturbances, the first motor state equation is established with speed error as the state variable: In the formula, For system state variables, This represents the desired rotational speed.

4. The sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation according to claim 3, characterized in that, For surface-mounted three-phase permanent magnet synchronous motors, the following requirements must be met. , where Ls is the inductance of the stator.

5. The sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation according to claim 2, characterized in that, The adaptive reaching law in step two is: In the formula, ; e It is a natural constant; The coefficients are the adaptive term coefficients, and sigmoid(·) is the function symbol; It is the linear amplification factor. It is a correction factor for the index. It is the coefficient of the exponential term. It is the coefficient of the power term. It is the linear amplification factor of the power term. This is a coefficient used to control the rate of change of the synovial surface index; Non-singular fast terminal sliding surface s The expression is: In the formula, , , , It is a positive odd number, and , .

6. The sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation according to claim 2, characterized in that, The speed loop controller expression in step two is: In the formula, i qref for q Desired value of shaft current For rotational inertia, e 1 represents the system state variable. The rotor's mechanical angular velocity, It is a permanent magnet flux chain. is the coefficient of viscous friction.

7. The sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation according to claim 2, characterized in that, The design process of the sliding mode perturbation observer in step four is as follows: Based on the rotor mechanical angular velocity and disturbance Establish the state equations for the second motor: The sliding mode disturbance observer equations are established by observing the rotor's mechanical angular velocity and disturbances: In the formula , For observer gain, For perturbation sliding mode gain, For electromagnetic torque, These are observed values ​​of mechanical angular velocity. These are perturbation observations.

8. The sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation according to claim 2, characterized in that, Step Two The function is: 。 9. A sliding mode control method for a permanent magnet synchronous motor based on disturbance compensation according to claim 2, characterized in that, The FOC speed control method for the permanent magnet synchronous motor in step five is as follows: Step S1: Collect the rotor position of the permanent magnet synchronous motor using sensors. Rotor angular velocity Three-phase current signals are acquired through a current sampling unit. , and ; Step S2: The sliding mode disturbance observer measures the rotor's mechanical angular velocity and rotational speed. The coordinate transformation module is used to obtain the three-phase current signal. The axis current is used to calculate the disturbance value that needs to be compensated and output the disturbance observation value. ; Step S3: The speed loop controller determines the desired rotational speed. Compared with the actual rotor mechanical angular velocity Errors and disturbances in observed values Update the output of the speed loop controller ; Step S4: The PI current loop controller, based on the given... Track the expected value of the shaft current and output. Desired value of shaft voltage , ; Step S5: For The shaft voltage undergoes Park inverse transformation and is input into the SVPWM module to complete the phase current regulation of the three-phase full-bridge inverter. Then, the inverter outputs control signals to drive the PMSM to operate. Repeat steps S1 to S5 to continuously provide feedback on the expected rotational speed. Compared with the actual rotor mechanical angular velocity To reduce errors and achieve speed control.

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