Asynchronous motor vector control method based on adaptive sliding mode observer

Abstract

The invention specifically discloses an asynchronous motor vector control method based on a self-adaptive sliding-mode observer, and the method comprises the steps: collecting three-phase currents ia, ib and ic of an industrial asynchronous motor stator, and converting a three-phase static current component into two-phase static current components # imgabs0 # and # imgabs1 # through a Clark conversion module; setting a self-adaptive sliding mode observer, and sending two-phase static current components # imgabs2 # and # imgabs3 # into a self-adaptive sliding mode observer module to obtain an estimated rotating speed # imgabs4 # and an estimated angle # imgabs5 #; obtaining reference voltage components ud and uq under a dq coordinate system through a proportional integral controller, and sending the reference voltage components ud and uq into a reverse Park conversion module to obtain two-phase static voltage components # imgabs6 # and # imgabs7 #; and the obtained two-phase static voltage components # imgabs8 # and # imgabs9 # are sent to an SVPWM module, and PWM pulses are generated to control the industrial asynchronous motor. According to the method, the motor state and unknown disturbance can be estimated in real time, so that the robustness and the control precision of the system are improved.

Description

Technical Field

[0001] The present invention relates to the field of industrial motor control, and in particular to an asynchronous motor vector control method based on an adaptive sliding mode observer. Background Art

[0002] In the field of industrial automation, asynchronous motors (also known as induction motors) are widely used in various mechanical drive systems due to their simple structure, high reliability, and low cost. To improve the dynamic performance and control accuracy of asynchronous motors, vector control (or field-oriented control) technology is widely adopted. Vector control technology converts the motor's three-phase current into two independent DC components (torque and flux), enabling precise motor control similar to that of a DC motor.

[0003] However, in practical applications, industrial asynchronous motor control systems often face challenges such as system parameter uncertainty, external disturbances, measurement noise, and nonlinear characteristics. These factors can affect motor performance, especially in highly dynamic conditions, potentially leading to performance degradation or even instability. Traditional vector control methods typically rely on precise motor parameters and reliable sensor data. However, due to issues such as motor parameter variations and sensor noise, stability and robustness may not be guaranteed.

[0004] Therefore, it is of great significance to effectively improve the robustness, stability and control accuracy of the motor system, adapt to the complex and dynamic industrial environment, and meet the needs of modern industrial automation for high-performance motor control. Summary of the Invention

[0005] The purpose of the present invention is to provide an asynchronous motor vector control method based on an adaptive sliding mode observer to solve the problem that the existing industrial asynchronous motor control is easily affected by system parameters, external disturbances and noise, resulting in performance degradation and inability to ensure stability and robustness.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A vector control method for an industrial asynchronous motor based on an adaptive sliding mode observer, comprising:

[0008] Collect the three-phase current i of the stator of the industrial asynchronous motor a 、i b and i c , the three-phase static current component is converted into a two-phase static current component through the Clark transformation module and ;

[0009] Set up an adaptive sliding mode observer to transform the two-phase static current components and Send it to the adaptive sliding mode observer module to get the estimated speed and estimated angle ;

[0010] Estimated speed and actual speed ω r After making the difference, the speed error is sent to the proportional integral controller to obtain the q-axis current reference value i q * ;

[0011] Based on the two-phase static current components and , and estimated angles , the two-phase rotating current components in the dq coordinate system are obtained through the Park transformation module and ;

[0012] The d-axis current reference value in the dq coordinate system is * and q-axis current * and the corresponding and After the difference is made, the current error in the dq coordinate system is sent to the proportional integral controller to obtain the reference voltage component u in the dq coordinate system. d and u q ;

[0013] The reference voltage component u in the dq coordinate system d and u q Send it to the inverse Park transformation module to obtain the two-phase static voltage components and ;

[0014] The two-phase static voltage components will be obtained and The signal is fed into the SVPWM module to generate PWM pulses to control the industrial asynchronous motor.

[0015] Preferably, an adaptive sliding mode observer is provided, comprising:

[0016] Establish the mathematical model of industrial asynchronous motor in two-phase stationary coordinate system;

[0017] Establish the observation equation and state variable error equation of the adaptive sliding mode observer;

[0018] Design of sliding mode gain of adaptive sliding mode observer based on Lyapunov function;

[0019] Define the Lyapunov function for the speed identification equation;

[0020] Obtain the speed identification equation for the adaptive sliding mode observer.

[0021] Preferably, the mathematical model is:

[0022] ; Among them, the state matrices B1, B2, B3, B4 and B5 satisfy: B1=aI, B2=bI-cJ, B3=fI, B4=dI, B5=-β(bI-cJ);

[0023] Matrices I and J satisfy: ;

[0024] The state variables stator current and rotor flux are expressed as: ;

[0025] in, ;

[0026] ω r is the rotor speed, i s is the stator current, i sa and i sβ is the component of the stator current on the α-axis and β-axis, Ψ r is the rotor flux, Ψ rα and Ψ rβ is the component of the rotor flux on the α-axis and the β-axis, σ is the leakage inductance, T r is the rotor time constant, R s is the stator resistance, R r is the rotor resistance, L s is the stator inductance, L r is the rotor inductance, L m is the mutual inductance, p is the differential operator, and T is the matrix transpose symbol.

[0027] Preferably, the observation equation and state variable error equation of the adaptive sliding mode observer are expressed as:

[0028] ,

[0029] in, , is the estimated rotor flux, is the estimated constant current, is the rotor speed error, J is the rotor moment of inertia, K1 and K2 are the sliding mode gains, and sgn(x) is the sign function.

[0030] Preferably, the sliding mode gains K1 and K2 satisfy the following conditions:

[0031] ;

[0032] Among them, among them, is the component of the rotor flux observation error in the αβ coordinate system, which can be expressed as and ; Estimate the magnetic flux component of the β axis in the αβ coordinate system, Estimate the magnetic flux component of the β axis in the αβ coordinate system, Estimate the flux linkage component for the α-axis in the αβ coordinate system.

[0033] Preferably, the Lyapunov function used for the speed identification equation is defined as:

[0034] , where V is the Lyapunov function defined for the speed identification equation, is the rotor flux observation error.

[0035] Preferably, the speed identification equation of the adaptive sliding mode observer is expressed as:

[0036] ,

[0037] Among them, k p is the scaling factor, k i is the integrating factor.

[0038] Preferably, the vector control method for constructing an adaptive sliding mode observer includes:

[0039] Based on estimated speed and the stator voltage component u in the αβ coordinate system sα 、u sβ , the stator current observer in the observation equation of the adaptive sliding mode observer is used to calculate the estimated stator current component in the αβ coordinate system and ;

[0040] Then the estimated stator current components in the αβ coordinate system are and The flux observer in the observation equation of the adaptive sliding mode observer is used to calculate the estimated flux component in the αβ coordinate system. and ;

[0041] Based on the discriminant equation of the estimated speed, the estimated stator current component in the αβ coordinate system is and With the actual current component and Subtract them respectively, then send the two differences into the sign function sgn(x) and multiply them by the corresponding gains K1 and K2 respectively;

[0042] The obtained results are compared with the estimated magnetic flux components in the αβ coordinate system and Multiply, and subtract the component corresponding to the α axis from the component corresponding to the β axis;

[0043] Finally, the result is fed into the proportional integral controller to obtain the estimated speed and estimated angle .

[0044] The present invention aims to provide an asynchronous motor vector control method based on an adaptive sliding mode observer. This method combines the advantages of adaptive sliding mode control and vector control. By introducing an adaptive mechanism to dynamically adjust the parameters of the sliding mode observer, it can estimate the motor state and unknown disturbances in real time, thereby improving the robustness and control accuracy of the system. This method addresses the problem that existing industrial asynchronous motor control is susceptible to system parameters, external disturbances, and noise, resulting in performance degradation and a lack of guaranteed stability and robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments.

[0046] Figure 1 A schematic diagram of an asynchronous motor vector control method based on an adaptive sliding mode observer provided by the present invention;

[0047] Figure 2 It is a flow chart of the setting of the adaptive sliding mode observer provided by the present invention.

[0048] Figure 3 A system block diagram of an adaptive sliding mode observer provided by an embodiment of the present invention;

[0049] Figure 4 A block diagram of industrial motor vector control based on an adaptive sliding mode observer provided in an embodiment of the present invention;

[0050] Figure 5 A schematic diagram of the actual speed and estimated speed when the speed suddenly changes under the vector control of an industrial motor based on an adaptive sliding mode observer provided by an embodiment of the present invention;

[0051] Figure 6 Schematic diagram of actual speed and estimated speed when electronic resistance and rotor resistance increase by 15% according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the solutions of the embodiments of the present invention, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings and implementation methods.

[0053] Aiming at the problem that current industrial asynchronous motor control is easily affected by system parameters, external disturbances and measurement noise, the purpose of the present invention is to provide an asynchronous motor vector control method based on an adaptive sliding mode observer to solve the problem that existing industrial asynchronous motor control is easily affected by system parameters, external disturbances and noise, resulting in performance degradation and inability to ensure stability and robustness.

[0054] like Figure 1 As shown, a vector control method for an industrial asynchronous motor based on an adaptive sliding mode observer includes:

[0055] S1: Collect the three-phase current i of the stator of the industrial asynchronous motor a 、i b and i c , the three-phase static current component is converted into a two-phase static current component through the Clark transformation module and ;

[0056] S2: Set up an adaptive sliding mode observer to convert the two-phase static current components and Send it to the adaptive sliding mode observer module to get the estimated speed and estimated angle ;

[0057] S3: Estimated speed and actual speed ω r After making the difference, the speed error is sent to the proportional integral controller to obtain the q-axis current reference value i q * ;

[0058] S4: Based on two-phase static current components and , and estimated angles , the two-phase rotating current components in the dq coordinate system are obtained through the Park transformation module and ;

[0059] S5: Set the d-axis current reference value in the dq coordinate system respectively * and q-axis current * and the corresponding and After the difference is made, the current error in the dq coordinate system is sent to the proportional integral controller to obtain the reference voltage component u in the dq coordinate system. d and u q ;

[0060] S6: The reference voltage component u in the dq coordinate system d and u qSend it to the inverse Park transformation module to obtain the two-phase static voltage components and ;

[0061] S7: The two-phase static voltage components will be obtained and The signal is fed into the SVPWM module to generate PWM pulses to control the industrial asynchronous motor.

[0062] like Figure 2 As shown in Figure 2, setting up an adaptive sliding mode observer includes the following steps:

[0063] (1): Establish a mathematical model of industrial asynchronous motor in a two-phase stationary coordinate system;

[0064] (2): Establish the observation equation and state variable error equation of the adaptive sliding mode observer;

[0065] (3): Design of sliding mode gain of adaptive sliding mode observer based on Lyapunov function;

[0066] (4) Define the Lyapunov function for the speed identification equation;

[0067] (5) Obtain the speed identification equation of the adaptive sliding mode observer;

[0068] (6) Construct a vector control method of adaptive sliding mode observer based on the above equations;

[0069] Furthermore, the following steps are included to establish a mathematical model of the industrial asynchronous motor in a two-phase stationary coordinate system:

[0070] In a two-phase stationary reference coordinate system, the industrial asynchronous motor establishes equations with stator current and rotor flux as state variables. The mathematical model of the industrial asynchronous motor in a two-phase stationary coordinate system is expressed as:

[0071] ; (1)

[0072] Among them, the state matrices B1, B2, B3, B4 and B5 satisfy: B1=aI, B2=bI-cJ, B3=fI, B4=dI, B5=-β(bI-cJ); among them, the matrices I and J satisfy:

[0073] ; (2)

[0074] The state variables stator current and rotor flux are expressed as,

[0075] ; (3)

[0076] in,

[0077] ; (4)

[0078] Among them, ω r is the rotor electrical angular velocity, i s is the stator current, i sa and i sβ is the component of the stator current on the α-axis and β-axis, Ψ r is the rotor flux, Ψ rα and Ψ rβ is the component of the rotor flux on the α-axis and the β-axis, σ is the leakage inductance, T r is the rotor time constant, R s is the stator resistance, R r is the rotor resistance, L s is the stator inductance, L r is the rotor inductance, L m is the mutual inductance, p is the differential operator, and T is the matrix transpose symbol.

[0079] Furthermore, the following steps are included to establish the observation equation and the state variable error equation of the adaptive sliding mode observer:

[0080] Define the sliding mode equation function,

[0081] ; (5)

[0082] Among them, the ones with “^” are estimates.

[0083] Furthermore, the observation equation of the adaptive sliding mode observer is expressed as,

[0084] ; (6)

[0085] The sliding mode switching function is the sign function sgn(x), which satisfies:

[0086] ; (7)

[0087] Among them, K1 and K2 are sliding mode gains, satisfying:

[0088] ; (8)

[0089] Based on Equation (1) and Equation (6), the observation equation and state variable error equation of the adaptive sliding mode observer can be expressed as:

[0090] ; (9)

[0091] in,

[0092] ; (10)

[0093] Furthermore, the following steps are included to establish a sliding mode gain for designing an adaptive sliding mode observer based on a Lyapunov function:

[0094] Define the Lyapunov function as:

[0095] ; (11)

[0096] Furthermore, Lyapunov's stability theory states , formula (11) is expanded to obtain:

[0097] ; (12)

[0098] From (12), we can see that the sliding mode gains k1 and k2 need to satisfy the following conditions:

[0099] ; (13)

[0100] When the stator current error trajectory reaches the sliding mode surface, the estimated stator current is the same as the actual stator current, that is:

[0101] e is =pe is =0; (14)

[0102] Furthermore, formula (9) becomes:

[0103] ; (15)

[0104] ; (16)

[0105] In (15) and (16), it satisfies ;

[0106] The error equation at this time is:

[0107] ; (17)

[0108] From (15), the vector form of the flux linkage error can be obtained as:

[0109] ; (18)

[0110] Furthermore, the following steps are included to define a Lyapunov function for the speed identification equation:

[0111] In order to derive the estimated speed identification equation, another Lyapunov function is defined:

[0112] ; (19)

[0113] In (19), β is greater than zero, so V is positive definite and the derivative of V is:

[0114] ; (20)

[0115] ;(twenty one)

[0116] (twenty two)

[0117] ;(twenty three)

[0118] In equations (22) and (23), Z = L - βI.

[0119] when When is less than zero, in this case, the observer satisfies the Lyapunov stability theory.

[0120] for (Optional):

[0121] ;(twenty four)

[0122] Equation (24) can be obtained under the following conditions .

[0123] ; (25)

[0124] Furthermore, the following steps are included to obtain the speed identification equation of the adaptive sliding mode observer:

[0125] In an asynchronous motor, the stator current and rotor flux change much faster than the actual speed, so the true speed of the asynchronous motor can be approximately kept constant in the speed estimation, that is, ; Therefore:

[0126] ; (26)

[0127] Substituting (26) into (25), we obtain the differential equation for estimating the speed:

[0128] ; (27)

[0129] In turn, the discriminant equation for estimating the rotational speed can be obtained as shown in (28):

[0130] ; (28)

[0131] In formula (28), k p is the scaling factor, k i is the integrating factor.

[0132] Furthermore, the following steps are included to construct an adaptive sliding mode observer according to the above equations:

[0133] Please see the attached Figure 3 , based on the estimated speed and the stator voltage component u in the αβ coordinate system sα 、u sβ , the stator current observer in the observation equation of the adaptive sliding mode observer shown in formula (6) is used to calculate the estimated stator current component in the αβ coordinate system and ; Then the estimated stator current components in the αβ coordinate system are and The flux observer in the observation equation of the adaptive sliding mode observer shown in Equation (6) is used to calculate the estimated flux component in the αβ coordinate system. and Based on formula (28), the estimated stator current component in the αβ coordinate system is and With the actual current component and Subtract them respectively, and then send the two differences into the sign function sgn(x), multiply them by the corresponding gains k1 and k2 respectively; further, the obtained results are respectively compared with the estimated magnetic flux components in the αβ coordinate system and Multiply, subtract the component corresponding to the α axis from the component corresponding to the β axis; finally, send the result to the proportional integral controller to get the estimated speed ;

[0134] Furthermore, the following steps are included to construct a vector control method of an adaptive sliding mode observer according to the above equation:

[0135] Please see the attached Figure 4 The vector control method of the adaptive sliding mode observer includes: a speed outer loop control module; a current inner loop control module, a Park transformation module, an inverse Park transformation module, a Clark transformation module, an SVPWM module and an adaptive sliding mode observer module;

[0136] First, collect the three-phase current i of the industrial asynchronous motor stator a 、i b and i c , the three-phase static current component is converted into a two-phase static current component through the Clark transformation module and ; Then, the two-phase static current components and Send it to the adaptive sliding mode observer module to get the estimated speed and estimated angle ; In the speed outer loop control module, the estimated speed and actual speed ω r After making the difference, the speed error is sent to the proportional integral controller to obtain the q-axis current reference value i q * ; Based on the two-phase static current components and , and estimated angles , the two-phase rotating current components in the dq coordinate system are obtained through the Park transformation module and ; In the current inner loop control module, the reference values ​​in the dq coordinate system are respectively * and * With actual value and After the difference is made, the current error in the dq coordinate system is sent to the proportional integral controller to obtain the reference voltage component u in the dq coordinate system. d and u q ; Further, the reference voltage component u in the dq coordinate system d and u q Send it to the inverse Park transformation module to obtain the two-phase static voltage components and ; Finally, the two-phase static voltage components will be obtained and The signal is sent to the SVPWM module to generate PWM pulses for controlling industrial asynchronous motors.

[0137] To verify the correctness of the proposed method, a simulation model of an industrial motor vector control system based on an adaptive sliding mode observer was constructed using MATLAB / SIMULINK simulation software. The specific parameters of the industrial motor are shown in Table 1.

[0138]

[0139] Please see the attached Figure 5 , the performance of the adaptive sliding mode observer is studied under a steady load with a sudden speed change. The asynchronous motor starts at 1200 rpm under no-load condition, switches to 800 rpm after 2 seconds, and then switches to 1200 rpm at 4 seconds; Figure 4 It can be clearly seen that the observer responds well to sudden changes in velocity; during these changes, the estimated velocity is accurate and during dynamics, the estimated and actual velocity curves fit well.

[0140] Please see the attached Figure 6During motor operation, motor temperature increases, and with it, motor resistance. Therefore, the performance of the adaptive sliding mode observer was tested under conditions of constant speed, constant load, and varying motor resistance. Both the stator and rotor resistances were increased by 15%. The load torque was 20 N·m, and the given speed was 1200 rpm. It can be concluded that when both the rotor and stator resistances increase by 15%, the estimated and actual speed profiles are likely to be consistent. The speed estimation error is small and falls within an acceptable range. This demonstrates the robustness of the observer to variations in motor parameters.

[0141] Experimental and simulation results demonstrate that the asynchronous motor control system using this approach exhibits superior performance under varying operating conditions and load variations, including significantly improved control accuracy, enhanced stability, and reduced energy consumption. This research provides an effective solution for high-performance control of industrial asynchronous motors and has important practical implications for improving the overall reliability and efficiency of industrial automation systems.

[0142] As can be seen, the present invention provides an asynchronous motor vector control method based on an adaptive sliding mode observer. This method combines the advantages of adaptive sliding mode control and vector control. By introducing an adaptive mechanism to dynamically adjust the parameters of the sliding mode observer, it can estimate the motor state and unknown disturbances in real time, thereby improving the robustness and control accuracy of the system. This method addresses the problem that existing industrial asynchronous motor control is susceptible to system parameters, external disturbances, and noise, resulting in performance degradation and a lack of guaranteed stability and robustness.

[0143] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in this industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of protection of the technical solution of the present invention.

Claims

1. A vector control method for an asynchronous motor based on an adaptive sliding mode observer, characterized in that: include: Collect the three-phase current i of the stator of the industrial asynchronous motor a 、i b and i c , the three-phase static current component is converted into a two-phase static current component through the Clark transformation module and ; Set up an adaptive sliding mode observer to transform the two-phase static current components and Send it to the adaptive sliding mode observer module to get the estimated speed and estimated angle ; Estimated speed and the actual rotor speed ω r After making the difference, the speed error is sent to the proportional integral controller to obtain the q-axis current reference value i q * ; Based on the two-phase static current components 、 and estimated angle , the two-phase rotating current components in the dq coordinate system are obtained through the Park transformation module and ; The d-axis current reference value in the dq coordinate system is * and q-axis current * and the corresponding and After the difference is made, the current error in the dq coordinate system is sent to the proportional integral controller to obtain the reference voltage component u in the dq coordinate system. d and u q ; The reference voltage component u in the dq coordinate system d and u q Send it to the inverse Park transformation module to obtain the two-phase static voltage components and ; The two-phase static voltage components will be obtained and The signal is fed into the SVPWM module to generate PWM pulses to control the industrial asynchronous motor.

2. The asynchronous motor vector control method based on adaptive sliding mode observer according to claim 1, characterized in that: Set up the adaptive sliding mode observer, including: Establish the mathematical model of industrial asynchronous motor in two-phase stationary coordinate system; Establish the observation equation and state variable error equation of the adaptive sliding mode observer; Design of sliding mode gain of adaptive sliding mode observer based on Lyapunov function; Define the Lyapunov function for the speed identification equation; Obtain the speed identification equation of the adaptive sliding mode observer; A vector control method based on adaptive sliding mode observer is constructed.

3. The asynchronous motor vector control method based on adaptive sliding mode observer according to claim 2, characterized in that: The mathematical model is: ; Among them, the state matrices B1, B2, B3, B4 and B5 satisfy: B1=aI, B2=bI-cJ, B3=fI, B4=dI, B5=-β(bI-cJ); Matrices I and J satisfy: ; The state variables stator current and rotor flux are expressed as: ; in, ; ω r is the rotor speed, i s is the stator current, i sa and i sβ is the component of the stator current on the α-axis and β-axis, Ψ r is the rotor flux, Ψ rα and Ψ rβ is the component of the rotor flux on the α-axis and the β-axis, σ is the leakage inductance, T r is the rotor time constant, R s is the stator resistance, R r is the rotor resistance, L s is the stator inductance, L r is the rotor inductance, L m is the mutual inductance, p is the differential operator, and T is the matrix transpose symbol.

4. The asynchronous motor vector control method based on adaptive sliding mode observer according to claim 3, characterized in that: The observation equation and state variable error equation of the adaptive sliding mode observer are expressed as: ， in, , is the estimated rotor flux, is the estimated constant current, is the rotor speed error, J is the rotor moment of inertia, K1 and K2 are the sliding mode gains, and sgn(x) is the sign function.

5. The asynchronous motor vector control method based on adaptive sliding mode observer according to claim 4, characterized in that: The sliding mode gains K1 and K2 satisfy the following conditions: ； in, is the component of the rotor flux observation error in the αβ coordinate system, which can be expressed as and ; Estimate the magnetic flux component of the β axis in the αβ coordinate system, Estimate the magnetic flux component of the β axis in the αβ coordinate system, Estimate the flux linkage component for the α-axis in the αβ coordinate system.

6. The asynchronous motor vector control method based on adaptive sliding mode observer according to claim 5, characterized in that: The Lyapunov function used for speed identification equation is defined as: , where V is the Lyapunov function defined for the speed identification equation, is the rotor flux observation error.

7. The asynchronous motor vector control method based on adaptive sliding mode observer according to claim 6, characterized in that: The speed identification equation of the adaptive sliding mode observer is expressed as: ， Among them, k p is the scaling factor, k i is the integrating factor.

8. The asynchronous motor vector control method based on adaptive sliding mode observer according to claim 7, characterized in that: The vector control method for constructing an adaptive sliding mode observer includes: Based on estimated speed and the stator voltage component u in the αβ coordinate system sα 、u sβ , the stator current observer in the observation equation of the adaptive sliding mode observer is used to calculate the estimated stator current component in the αβ coordinate system and ; Then the estimated stator current components in the αβ coordinate system are and The flux observer in the observation equation of the adaptive sliding mode observer is used to calculate the estimated flux component in the αβ coordinate system. and ; Based on the discriminant equation of the estimated speed, the estimated stator current component in the αβ coordinate system is and With the actual current component and Subtract them respectively, then send the two differences into the sign function sgn(x) and multiply them by the corresponding gains K1 and K2 respectively; The obtained results are compared with the estimated magnetic flux components in the αβ coordinate system and Multiply, and subtract the component corresponding to the α axis from the component corresponding to the β axis; Finally, the result is fed into the proportional integral controller to obtain the estimated speed and estimated angle .

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