Construction method of virtual voltage signal injection full-order flux linkage observer based on maximum torque current ratio

Abstract

A kind of maximum torque current ratio-based full-order flux linkage observer virtual voltage signal generation method belongs to motor position sensorless control technical field.The present application aims at the problem that the amplitude of existing virtual voltage signal injection based on full-order flux linkage observer is extremely difficult to adjust,which cannot realize stable operation under different load conditions at zero speed.The present application includes the following steps: constructing full-order flux linkage observer based on the voltage equation of built-in permanent magnet synchronous motor under estimated rotating shaft system;linearizing decoupling the flux linkage error dynamic equation of full-order flux linkage observer at local point to obtain the mathematical expression relationship between position estimation error of full-order flux linkage observer and virtual voltage signal;then establishing the relationship between position estimation error and torque of built-in permanent magnet synchronous motor;setting position estimation error as maximum torque current ratio angle,calculating to obtain the injection coefficient of virtual voltage signal;generating virtual voltage signal based on the injection coefficient.The present application can realize parameter tuning of motor position observer.

Description

Technical Field

[0001] This invention relates to a method for constructing a full-order flux linkage observer based on the virtual voltage signal injection of the maximum torque-current ratio, belonging to the field of sensorless motor control technology. Background Technology

[0002] Since Field-Oriented Control (FOC) is the most commonly used method for motor control, it requires precise rotor angle and speed. Therefore, encoders are a crucial component of motor drive control systems. However, under extreme operating conditions, encoder reliability becomes a significant factor hindering system stability and increasing system costs. Consequently, sensorless technology has remained a hot topic in academic research.

[0003] Depending on whether a signal is injected, sensorless technology can be divided into signal injection methods based on tracking the salient polarity of the motor rotor and model methods based on observing the back EMF / magnetic flux of the motor. To achieve sensorless control of low-speed permanent magnet synchronous motors, signal injection methods based on tracking the salient polarity of the motor rotor are generally used. This type of method identifies the motor rotor position by injecting a voltage signal. The vibration and sharp high-frequency noise brought by the high-frequency voltage signal are almost unavoidable, which limits the application of this method in high-precision manufacturing and noise-sensitive industries. However, in some application scenarios, the sensorless motor system is required to have zero-speed full-torque capability. Therefore, position and speed observation technology based on model methods at zero speed is very important.

[0004] Currently, a commonly used method for zero-speed model operation is the method based on injecting virtual voltage signals into a full-order flux linkage observer. However, the amplitude of the virtual voltage signal injection is extremely difficult to adjust, making stable operation impossible under different load conditions. Therefore, a virtual voltage signal injection adjustment method suitable for different load conditions is of great significance. Summary of the Invention

[0005] To address the problem that the amplitude of the virtual voltage signal injection based on the existing full-order flux linkage observer is extremely difficult to adjust, and cannot achieve stable operation under different load conditions at zero speed, this invention provides a method for constructing a virtual voltage signal injection full-order flux linkage observer based on the maximum torque-current ratio.

[0006] The present invention provides a method for constructing a full-order flux linkage observer based on virtual voltage signal injection with maximum torque-current ratio, which constructs a full-order flux linkage observer based on estimating the voltage equation of a built-in permanent magnet synchronous motor under a rotating shaft system.

[0007] The dynamic equation of the flux linkage error of the full-order flux linkage observer is linearized and decoupled at local points to obtain a mathematical expression of the relationship between the position estimation error of the full-order flux linkage observer and the virtual voltage signal.

[0008] Then, establish the relationship between the position estimation error and the torque of the built-in permanent magnet synchronous motor;

[0009] The position estimation error is set to the maximum torque current ratio angle, and the injection coefficient of the virtual voltage signal is calculated.

[0010] A virtual voltage signal is generated based on the injection coefficient.

[0011] According to the method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio of the present invention, the voltage equation of the built-in permanent magnet synchronous motor under the rotating shaft system is estimated as follows:

[0012] (1),

[0013] In the formula To estimate the stator voltage of the rotating shaft system, ,in To estimate the stator voltage of the γ-axis rotating shaft system, To estimate the stator voltage of the δ-axis of the rotating shaft system, For stator resistance, To estimate the stator current of the rotating shaft system, , To estimate the stator current of the γ-axis of the rotating shaft system, To estimate the stator current of the δ-axis of the rotating shaft system, For stator flux linkage, This is an estimated value for the electric angular velocity. It is an orthogonal matrix;

[0014] ,

[0015] In the formula For the inductor matrix, Let be the flux linkage vector of the permanent magnet. , It is a permanent magnet flux chain. To estimate the stator flux linkage of the γ-axis rotating shaft system, To estimate the stator flux linkage along the δ-axis of the rotating shaft system;

[0016] ,

[0017] In the formula For the actual rotating shaft system, the d-axis inductance. For the actual rotating shaft system, the q-axis inductance;

[0018] .

[0019] According to the present invention, the virtual voltage signal injection full-order flux linkage observer based on the maximum torque-current ratio is constructed as follows:

[0020] (2),

[0021] In the formula This is the estimated value of the stator flux linkage. To estimate the stator current of the rotating shaft system, ; The observer gain matrix is... To estimate the current error of the rotating shaft system, ;

[0022] ,

[0023] In the formula For the feedback gain matrix, It is the identity matrix. K = kI, which is the feedback gain coefficient.

[0024] According to the present invention, the virtual voltage signal injection full-order flux linkage observer based on the maximum torque-current ratio is used to construct the full-order flux linkage observer by adopting a velocity adaptive rate to observe the estimated electric angular velocity. :

[0025] (3),

[0026] In the formula For the speed adaptive rate gain coefficient, For generalized position error, The integral coefficient of the speed adaptive rate, For time;

[0027] ,

[0028] In the formula The generalized error projection vector. , This is an estimated value for the q-axis inductance of the actual rotating shaft system. To estimate the stator current of the δ-axis of the rotating shaft system;

[0029] , ,

[0030] In the formula This is an estimated value for the flux linkage of the permanent magnet. This represents the bandwidth coefficient.

[0031] According to the method for constructing a full-order flux linkage observer based on virtual voltage signal injection with maximum torque-current ratio according to the present invention, the dynamic equation of flux linkage error of the full-order flux linkage observer is expressed as:

[0032] (4),

[0033] In the formula For flux linkage estimation error, .

[0034] According to the method for constructing a full-order flux linkage observer based on virtual voltage signal injection with maximum torque-current ratio of the present invention, the flux linkage error dynamic equation of the full-order flux linkage observer is linearized and decoupled at local points to obtain:

[0035] ,

[0036] In the formula, the variable with the subscript 0 represents the corresponding variable value at the steady-state operating point; To estimate the stator flux linkage at the steady-state operating point of the rotating shaft system, For position estimation error, , This represents the actual position of the rotor. Estimate the position of the rotor;

[0037] ,

[0038] In the formula This is an estimated value for the d-axis inductance of the actual rotating shaft system;

[0039] After injecting the virtual voltage signal, the dynamic equation for the linearized flux estimation error of the full-order flux observer is:

[0040] (5),

[0041] In the formula To estimate the virtual voltage of the rotating shaft system;

[0042] When the system is at its steady-state operating point, the generalized position error Converging to 0; decoupling yields the position estimation error of the full-order flux linkage observer and the estimated virtual voltage of the rotating axis system. The mathematical expression of the relation:

[0043] (6),

[0044] In the formula For complex variables in the frequency domain;

[0045] Simplifying formula (6), we get:

[0046] (7),

[0047] In the formula To estimate the virtual voltage of the γ-axis in a rotating axis system, To estimate the δ-axis virtual voltage in a rotating axis system.

[0048] According to the method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio of the present invention, the relationship between the position estimation error and the torque of the built-in permanent magnet synchronous motor is established as follows:

[0049] (8),

[0050] In the formula For torque, This represents the current amplitude at the motor's operating point.

[0051] According to the present invention, the method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio expresses the maximum torque-current ratio angle as follows: :

[0052] (9).

[0053] According to the method for constructing a full-order flux linkage observer based on virtual voltage signal injection with maximum torque-current ratio according to the present invention, the position estimation error is set. The maximum torque-to-current ratio angle is expressed as: :

[0054] (10)

[0055] Estimate the virtual voltage of the rotating shaft system after the rotor speed decreases to 0. With estimation of virtual current of rotating shaft system The relationship can be approximated as:

[0056] (11),

[0057] In the formula To estimate the virtual current along the γ-axis of the rotating shaft system, To estimate the virtual current of the δ-axis of the rotating shaft system;

[0058] Because i γ_vir ≈0, then i δ_vir Represented as:

[0059] (12)

[0060] In the formula This is an estimated value for the stator resistance;

[0061] The amplitude and stability of the virtual voltage injection can be adjusted by regulating the injection coefficient of the virtual voltage signal.

[0062] According to the present invention, the virtual voltage signal injection full-order flux linkage observer construction method based on maximum torque-current ratio, when the feedback gain coefficient When the injection coefficient is m, it is represented as:

[0063] (13)

[0064] In the formula This is the adjustment coefficient.

[0065] The beneficial effects of this invention are as follows: By deriving and designing the virtual voltage signal injection coefficients, the method of this invention determines the injected virtual voltage signal, ensuring the stability of the observer when operating at zero speed. It also enables parameter tuning of the motor position observer.

[0066] This invention provides a method for adjusting the virtual voltage signal injection coefficient based on a full-order flux linkage observer under different load conditions. It constructs a full-order flux linkage observer based on the motor voltage equations of the estimated shaft system; and obtains a mathematical expression relationship between the position estimation error of the full-order flux linkage observer and the virtual voltage signal through the observer's error dynamic equation and linear decoupling at local points; simultaneously, it establishes a relationship between the sensorless position estimation error and the torque of the built-in permanent magnet synchronous motor; and by setting the position estimation error to the maximum torque-to-current ratio angle, it obtains a method for generating the virtual voltage signal coefficients. Compared to traditional trial-and-error parameter adjustment methods, this invention can adaptively obtain the amplitude of the virtual voltage signal to be injected according to different load conditions, thus possessing practical value. Attached Figure Description

[0067] Figure 1 This is a block diagram illustrating the principle of the virtual voltage signal injection full-order flux linkage observer construction method based on the maximum torque-current ratio described in this invention for sensorless vector control of motors; the diagram shows... The given speed for the outer ring of rotational speed. To estimate the given value of the stator current of the rotating shaft system δ-axis, To estimate the given value of the stator current of the rotating shaft system γ-axis; To estimate the setpoint value of the stator voltage along the δ-axis of the rotating shaft system, To estimate the setpoint value of the stator voltage on the γ-axis of the rotating shaft system, The given value for the voltage along the α-axis of the stationary axis system. stationary axis system Shaft voltage setpoint, t d For dead time, i a Let i be the phase current value. c This represents the c-phase current value. For the α-axis current of the stationary axis, stationary axis system shaft current, Voltage of the stationary axis Current in a stationary axis system;

[0068] Figure 2This is a schematic diagram of the reference coordinate system for constructing a full-order flux linkage observer based on the virtual voltage signal injection of the maximum torque-current ratio as described in this invention; where the α-β axis represents the stationary axis system, the dq axis represents the actual rotating axis system, and the γ-δ axis represents the estimated rotating axis system; This represents the true value of the electric angular velocity;

[0069] Figure 3 This is the overall control block diagram of the method for constructing a full-order flux linkage observer based on virtual voltage signal injection with maximum torque-current ratio as described in this invention; the diagram shows... For projection coefficients, ; The voltage across the α-axis of the stationary axis system. stationary axis system shaft voltage, For the switching time of phase a, For phase b switching time, For the c-phase switching time, i b This represents the phase b current value.

[0070] Figure 4 This is a position estimation error diagram under light load conditions without injected virtual voltage signal;

[0071] Figure 5 This is a position estimation error diagram based on the method of the present invention under light load conditions;

[0072] Figure 6 This is a position estimation error diagram under heavy load conditions without injected virtual voltage signal;

[0073] Figure 7 This is a position estimation error diagram based on the method of this invention under heavy load conditions. Detailed Implementation

[0074] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0075] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0076] The present invention will be further described below with reference to the accompanying drawings, but this should not be construed as limiting the invention.

[0077] Specific Implementation Method 1: Combination Figures 1 to 3As shown, this invention provides a method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-to-current ratio, including:

[0078] A full-order flux linkage observer is constructed based on the estimated voltage equations of the built-in permanent magnet synchronous motor in the rotating shaft system;

[0079] The dynamic equation of the flux linkage error of the full-order flux linkage observer is linearized and decoupled at local points to obtain a mathematical expression of the relationship between the position estimation error of the full-order flux linkage observer and the virtual voltage signal.

[0080] Then, establish the relationship between the position estimation error and the torque of the built-in permanent magnet synchronous motor;

[0081] The position estimation error is set to the maximum torque current ratio angle, and the injection coefficient of the virtual voltage signal is calculated.

[0082] A virtual voltage signal is generated based on the injection coefficient.

[0083] When used for sensorless vector control of a motor, the virtual voltage signal is adjusted based on the injection coefficient of the virtual voltage signal, and the rotor position and rotor speed at zero speed are observed using the full-order flux linkage observer to obtain the rotor position observation value and rotor speed observation value. The rotor position observation value and rotor speed observation value are fed back to the dual closed-loop control system to realize sensorless vector control of the motor at zero speed.

[0084] In this embodiment, the observer flux error equation is obtained by linearization, and the virtual voltage signal term and position estimation error in the equation are decoupled. Finally, a virtual voltage signal adjustment method is designed to achieve parameter tuning and stable operation under different operating conditions.

[0085] Combination Figures 1 to 3 Further explanation of this embodiment, such as Figure 2 The diagram shows the reference coordinate system of this invention. The α-β axis, dq axis, and γ-δ axis represent the stationary, actual rotating, and estimated rotating axes, respectively. The observer output position alignment is defined. The position estimation error of the axis is expressed as , and These are the actual and estimated electric angular velocities of the motor, respectively.

[0086] like Figure 3The diagram shows the overall control block diagram of this embodiment, including dual closed-loop control, a full-order flux linkage observer, and a virtual voltage signal generation method based on the maximum torque-to-current ratio for the full-order flux linkage observer. When the system is in dual closed-loop vector control, the outer speed loop outputs the current given current by comparing the given speed with the observed speed value. The inner current loop obtains the voltage control signal required by SVPWM by comparing the given current with the acquired real current. The voltage signal is modulated by the SVPWM module and then sent to the inverter to achieve motor control. This embodiment realizes the observation of rotor position and speed information, and uses the observed rotor position and speed information to complete sensorless closed-loop control.

[0087] Furthermore, the voltage equation for the built-in permanent magnet synchronous motor under the rotating shaft system is estimated as follows:

[0088] (1),

[0089] In the formula To estimate the stator voltage of the rotating shaft system, ,in To estimate the stator voltage of the γ-axis rotating shaft system, To estimate the stator voltage of the δ-axis of the rotating shaft system, For stator resistance, To estimate the stator current of the rotating shaft system, , To estimate the stator current of the γ-axis of the rotating shaft system, To estimate the stator current of the δ-axis of the rotating shaft system, For stator flux linkage, This is an estimated value for the electric angular velocity. It is an orthogonal matrix;

[0090] ,

[0091] In the formula For the inductor matrix, Let be the flux linkage vector of the permanent magnet. , It is a permanent magnet flux chain. To estimate the stator flux linkage of the γ-axis rotating shaft system, To estimate the stator flux linkage along the δ-axis of the rotating shaft system;

[0092] ,

[0093] In the formula For the actual rotating shaft system, the d-axis inductance. For the actual rotating shaft system, the q-axis inductance;

[0094] .

[0095] Introducing the error between the estimated current and the actual current as the observer feedback term, the full-order flux linkage observer for the estimated axis system is expressed as follows:

[0096] (2),

[0097] In the formula This is the estimated value of the stator flux linkage. To estimate the stator current of the rotating shaft system, the stator flux linkage is estimated. By reverse deduction, ; The observer gain matrix is... To estimate the current error of the rotating shaft system, ;

[0098] ,

[0099] In the formula For the feedback gain matrix, It is the identity matrix. K = kI, which is the feedback gain coefficient.

[0100] The full-order flux linkage observer uses a velocity adaptive rate to observe the electric angular velocity estimate. :

[0101] (3),

[0102] In the formula For the speed adaptive rate gain coefficient, For generalized position error, The integral coefficient of the speed adaptive rate, For time;

[0103] ,

[0104] In the formula The generalized error projection vector. , This is an estimated value for the q-axis inductance of the actual rotating shaft system. To estimate the stator current of the δ-axis of the rotating shaft system;

[0105] , ,

[0106] In the formula This is an estimated value for the flux linkage of the permanent magnet. This represents the bandwidth coefficient.

[0107] Furthermore, the dynamic equation for the flux linkage error of the full-order flux linkage observer is expressed as:

[0108] (4),

[0109] In the formula For flux linkage estimation error, .

[0110] In this embodiment, the dynamic equation of the flux linkage error of the full-order flux linkage observer is decoupled by linearization at local points to obtain the linearized dynamic equation of the flux linkage error of the observer:

[0111] ,

[0112] In the formula, the variable with the subscript 0 represents the corresponding variable value at the steady-state operating point; To estimate the stator flux linkage at the steady-state operating point of the rotating shaft system, For position estimation error, , This represents the actual position of the rotor. Estimate the position of the rotor;

[0113] ,

[0114] In the formula This is an estimated value for the d-axis inductance of the actual rotating shaft system;

[0115] After injecting the virtual voltage signal, the dynamic equation for the linearized flux estimation error of the full-order flux observer is:

[0116] (5),

[0117] In the formula To estimate the virtual voltage of the rotating shaft system;

[0118] When the system is at its steady-state operating point, the generalized position error Converging to 0; decoupling yields the position estimation error of the full-order flux linkage observer and the estimated virtual voltage of the rotating axis system. The mathematical expression of the relation:

[0119] (6),

[0120] In the formula For complex variables in the frequency domain;

[0121] Simplifying formula (6), we get:

[0122] (7),

[0123] In the formula To estimate the virtual voltage of the γ-axis in a rotating axis system, To estimate the δ-axis virtual voltage in a rotating axis system.

[0124] Furthermore, the relationship between the position estimation error and the torque of the built-in permanent magnet synchronous motor is established as follows:

[0125] (8),

[0126] In the formula For torque, This represents the current amplitude at the motor's operating point.

[0127] By combining the relationship between position estimation error and maximum torque-current ratio, the position estimation error of the motor is set to the MTPA angle of the built-in permanent magnet synchronous motor, and the maximum torque-current ratio angle is expressed as... :

[0128] (9).

[0129] In this embodiment, the position estimation error is set. The maximum torque-to-current ratio angle is expressed as: :

[0130] (10)

[0131] Estimate the virtual voltage of the rotating shaft system after the rotor speed decreases to 0. With estimation of virtual current of rotating shaft system The relationship can be approximated as:

[0132] (11),

[0133] In the formula To estimate the virtual current along the γ-axis of the rotating shaft system, To estimate the virtual current of the δ-axis of the rotating shaft system;

[0134] Because i γ_vir ≈0, then i δ_vir Represented as:

[0135] (12)

[0136] In the formula This is an estimated value for the stator resistance;

[0137] The amplitude and stability of the virtual voltage injection can be adjusted by regulating the injection coefficient of the virtual voltage signal.

[0138] The virtual voltage injection amplitude and stability of the system can be adjusted by adjusting the virtual injection coefficient m. When the feedback gain coefficient... When the injection coefficient is m, it is represented as:

[0139] (13)

[0140] In the formula This is the adjustment coefficient.

[0141] Finally, by combining the full-order flux linkage observer with the virtual voltage signal coefficient generation method, the rotor position and speed at zero speed are observed; the rotor position and speed observation values ​​are fed back to the dual closed-loop control system to realize sensorless vector control of the motor.

[0142] Verification experiment:

[0143] This experiment was conducted on a permanent magnet synchronous motor (PMSM) tractor-mounted experimental platform. A 2.2kW built-in PMSM and an induction motor were coaxially connected via a coupling, with the built-in PMSM serving as the control motor and the induction motor as the load motor. Two frequency converters were connected via a common DC bus. A vector control algorithm was implemented using an STM32F103VCT6 ARM microcontroller to control the PMSM. The inverter switching frequency was 6kHz.

[0144] The main parameters of the permanent magnet synchronous motor used are: rated power 2.2kW, rated current 4.4A, rated speed 1500r / min, L d = 35mH, L q = 64mH, pole pair number P = 3, R = 2.75Ω.

[0145] like Figures 4 to 7 The figure shows the experimental results comparing the injection of virtual voltage signals before and after light load and full load conditions. The motor load was set to 10% of the rated load and the rated load. The motor decelerated from 200 r / min to zero speed under load. Figure 4 and Figure 6 It can be observed that without injecting a virtual voltage signal, when the motor is running near zero speed, the observer's position estimation error will diverge rapidly, causing the motor to lose control and ultimately triggering overcurrent protection. Figure 5 and Figure 7 It can be observed that when the virtual voltage signal is enabled, the observer can remain stable at zero speed.

[0146] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio, characterized in that, A full-order flux linkage observer is constructed based on the estimated voltage equations of the built-in permanent magnet synchronous motor in the rotating shaft system; The dynamic equation of the flux linkage error of the full-order flux linkage observer is linearized and decoupled at local points to obtain the mathematical expression of the position estimation error of the full-order flux linkage observer and the virtual voltage signal. Then, establish the relationship between the position estimation error and the torque of the built-in permanent magnet synchronous motor; The position estimation error is set to the maximum torque current ratio angle, and the injection coefficient of the virtual voltage signal is calculated. A virtual voltage signal is generated based on the injection coefficient; When the feedback gain coefficient When the injection coefficient is m, it is represented as: （13）， In the formula For adjustment coefficients, This is an estimated value for the electric angular velocity. To estimate the δ-axis virtual voltage in a rotating axis system, To estimate the stator voltage of the δ-axis of the rotating shaft system, The maximum torque-to-current ratio angle, To estimate the stator flux linkage at the steady-state operating point of the δ-axis of the rotating shaft system, For the actual rotating shaft system q-axis inductance, This is an estimated value for the stator resistance. To estimate the stator current of the δ-axis of the rotating shaft system.

2. The method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio according to claim 1, characterized in that, The voltage equation for the built-in permanent magnet synchronous motor under the rotating shaft system is estimated as follows: （1）， In the formula To estimate the stator voltage of the rotating shaft system, ,in To estimate the stator voltage of the γ-axis of the rotating shaft system, For stator resistance, To estimate the stator current of the rotating shaft system, , To estimate the stator current of the γ-axis of the rotating shaft system, For stator flux linkage, It is an orthogonal matrix; ， In the formula For the inductor matrix, Let be the flux linkage vector of the permanent magnet. , It is a permanent magnet flux chain. To estimate the stator flux linkage of the γ-axis rotating shaft system, To estimate the stator flux linkage along the δ-axis of the rotating shaft system; ， In the formula The actual d-axis inductance of the rotating shaft system; 。 3. The method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio according to claim 2, characterized in that, The full-order flux linkage observer is represented as: （2）， In the formula This is the estimated value of the stator flux linkage. To estimate the stator current of the rotating shaft system, ; The observer gain matrix is... To estimate the current error of the rotating shaft system, ; ， In the formula For the feedback gain matrix, It is the identity matrix. K = kI, which is the feedback gain coefficient.

4. The method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio according to claim 3, characterized in that, The full-order flux linkage observer uses a velocity adaptive rate to observe the electric angular velocity estimate. : （3）， In the formula For the speed adaptive rate gain coefficient, For generalized position error, The integral coefficient of the speed adaptive rate, For time; ， In the formula The generalized error projection vector. , This is an estimated value for the q-axis inductance of the actual rotating shaft system. To estimate the stator current of the δ-axis of the rotating shaft system; ， ， In the formula This is an estimated value for the flux linkage of the permanent magnet. This represents the bandwidth coefficient.

5. The method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio according to claim 4, characterized in that, The dynamic equation for the flux error of the full-order flux observer is expressed as follows: （4）， In the formula For flux linkage estimation error, .

6. The method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio according to claim 5, characterized in that, By linearizing and decoupling the dynamic equation of the flux error of the full-order flux observer at local points, we obtain: ， In the formula, the variable with the subscript 0 represents the corresponding variable value at the steady-state operating point; To estimate the stator flux linkage at the steady-state operating point of the rotating shaft system, For position estimation error, , This represents the actual position of the rotor. Estimate the position of the rotor; ， In the formula This is an estimated value for the d-axis inductance of the actual rotating shaft system; After injecting the virtual voltage signal, the dynamic equation for the linearized flux estimation error of the full-order flux observer is: （5）， In the formula To estimate the virtual voltage of the rotating shaft system; When the system is at its steady-state operating point, the generalized position error Converging to 0; decoupling yields the position estimation error of the full-order flux linkage observer and the estimated virtual voltage of the rotating axis system. The mathematical expression of the relation: （6）， In the formula For complex variables in the frequency domain; Simplifying formula (6), we get: （7）， In the formula To estimate the virtual voltage of the γ-axis in the rotating axis system.

7. The method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio according to claim 6, characterized in that, The relationship between the position estimation error and the torque of the built-in permanent magnet synchronous motor is established as follows: （8）， In the formula For torque, This represents the current amplitude at the motor's operating point.

8. The method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio according to claim 7, characterized in that, The maximum torque-current ratio angle is expressed as: : （9）。 9. The method for constructing a full-order flux linkage observer based on virtual voltage signal injection using the maximum torque-current ratio according to claim 8, characterized in that, Set the position estimation error The maximum torque-to-current ratio angle is expressed as: : （10）， Estimate the virtual voltage of the rotating shaft system after the rotor speed decreases to 0. With estimation of virtual current of rotating shaft system The relationship can be approximated as: （11）， In the formula To estimate the virtual current along the γ-axis of the rotating shaft system, To estimate the virtual current of the δ-axis of the rotating shaft system; Because i γ_vir ≈0, then i δ_vir Represented as: （12）； The amplitude and stability of the virtual voltage injection can be adjusted by regulating the injection coefficient of the virtual voltage signal.

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