Full-order flux observer virtual voltage signal generation method based on maximum torque current ratio

Abstract

The invention discloses a full-order flux observer virtual voltage signal generation method based on the maximum torque current ratio, and belongs to the technical field of motor position sensorless control. The problems that the injection amplitude of an existing virtual voltage signal based on a full-order flux linkage observer is very difficult to adjust, and stable operation cannot be achieved under different load working conditions at the zero speed are solved. Comprising the following steps: constructing a full-order flux observer based on a built-in permanent magnet synchronous motor voltage equation under an estimated rotating shaft system; performing linear decoupling on the flux linkage error dynamic equation of the full-order flux linkage observer on a local point to obtain a mathematical expression relational expression between the position estimation error of the full-order flux linkage observer and the virtual voltage signal; establishing a relation between the position estimation error and the torque of the built-in permanent magnet synchronous motor; setting a position estimation error as a maximum torque current ratio angle, and calculating to obtain an injection coefficient of a virtual voltage signal; and generating a virtual voltage signal based on the injection coefficient. According to the invention, parameter tuning of the motor position observer can be realized.

Description

Technical Field

[0001] The invention relates to a method for generating a virtual voltage signal of a full-order flux observer based on a maximum torque current ratio, and belongs to the technical field of motor position sensorless control. Background Art

[0002] As the most commonly used motor control method, FOC requires precise rotor angle and speed, so encoders become an important part of the motor drive control system. However, under extremely harsh working conditions, encoder reliability becomes an important factor that hinders system stability and increases system costs, so sensorless technology has always been a hot topic in academic research.

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

[0004] At present, the commonly used zero-speed model method is based on the virtual voltage signal injection full-order flux observer operation method, but the virtual voltage signal injection amplitude of this method is extremely difficult to adjust, and stable operation cannot be achieved 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] Aiming at the problem that the injection amplitude of the virtual voltage signal based on the existing full-order flux observer is extremely difficult to adjust and stable operation cannot be achieved under different load conditions at zero speed, the present invention provides a method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio.

[0006] A method for generating a virtual voltage signal of a full-order flux observer based on a maximum torque current ratio of the present invention constructs a full-order flux observer based on an estimated voltage equation of a built-in permanent magnet synchronous motor under a rotating shaft system;

[0007] Linearizing and decoupling the flux error dynamic equation of the full-order flux observer at a local point to obtain a mathematical expression relationship between the position estimation error of the full-order flux observer and the virtual voltage signal;

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

[0009] The position estimation error is set as 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 generating a virtual voltage signal of a full-order flux observer based on the maximum torque current ratio of the present invention, the voltage equation of the interior permanent magnet synchronous motor under the rotating shaft system is estimated to be:

[0012]

[0013] Where u γδ To estimate the stator voltage of the rotating shaft, u γδ =[u γ u δ ] T , where u γ To estimate the stator voltage of the rotating axis γ, u δ To estimate the stator voltage of the rotating shaft system δ axis, R s is the stator resistance, i γδ To estimate the stator current of the rotating shaft, i γδ =[i γ i δ ] T ,i γ To estimate the stator current of the γ-axis of the rotating shaft system, i δ To estimate the stator current of the rotating shaft system δ axis, ψ s is the stator flux, is the estimated value of electrical angular velocity, J is an orthogonal matrix;

[0014] ψ s =Li γδ +ψ f =[ψ γ ψ δ ] T ,

[0015] Where L is the inductance matrix, ψ f is the permanent magnet flux vector, ψ f =[ψ f1 0] T , ψ f1 is the permanent magnet flux, ψ γ To estimate the stator flux of the rotating axis γ, ψ δ To estimate the stator flux of the rotating axis δ-axis;

[0016] L=[L d ,0;0,L q ]T ,

[0017] Where L d is the d-axis inductance of the actual rotating axis system, L q is the q-axis inductance of the actual rotating axis system;

[0018] J=[0,-1;1,0].

[0019] According to the method for generating a virtual voltage signal of a full-order flux observer based on the maximum torque current ratio of the present invention, the full-order flux observer is expressed as:

[0020]

[0021] In the formula is the estimated value of stator flux, To estimate the stator current of the rotating shaft, λ is the observer gain matrix, To estimate the rotating shaft current error,

[0022]

[0023] Where K is the feedback gain matrix, I is the unit matrix, k is the feedback gain coefficient, K=kI.

[0024] According to the method for generating a virtual voltage signal of a full-order flux observer based on the maximum torque current ratio of the present invention, the full-order flux observer uses a speed adaptive rate to observe the estimated value of the electrical angular velocity.

[0025]

[0026] Where k p is the velocity adaptation rate gain coefficient, ε is the generalized position error, k i is the speed adaptation rate integral coefficient, t is the time;

[0027]

[0028] Where W0 is the generalized error projection vector, is the estimated value of the q-axis inductance of the actual rotating axis system, To estimate the stator current of the rotating shaft system δ axis;

[0029]

[0030] In the formula is the estimated value of permanent magnet flux linkage, and σ is the bandwidth coefficient.

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

[0032]

[0033] In the formula is the flux estimation error,

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

[0035]

[0036] The variables with subscript 0 in the formula represent the corresponding variable values ​​at the steady-state operating point; ψ γδ0 To estimate the stator flux at the steady-state operating point of the rotating shaft system, is the position estimation error, θ e is the true position of the rotor, Estimate the position for the rotor;

[0037]

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

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

[0040]

[0041] Where u γδ_vir To estimate the virtual voltage of the rotating shaft system;

[0042] When the system is at a steady-state operating point, the generalized position error ε converges to 0; the position estimation error of the full-order flux observer is decoupled from the estimated rotating shaft virtual voltage u γδ_vir The mathematical expression of the relationship is:

[0043]

[0044] Where s is a complex variable in the frequency domain;

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

[0046]

[0047] Where u γ_virTo estimate the virtual voltage of the γ axis under the rotating axis system, u δ_vir To estimate the virtual voltage of the δ-axis under the rotating shaft system.

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

[0049]

[0050] Where T e is the torque, I s is the current amplitude at the motor operating point.

[0051] According to the method for generating virtual voltage signal of full-order flux observer based on maximum torque current ratio of the present invention, the maximum torque current ratio angle is expressed as

[0052]

[0053] According to the method for generating a virtual voltage signal of a full-order flux observer based on the maximum torque current ratio of the present invention, the position estimation error is set The maximum torque current ratio angle is expressed as

[0054]

[0055] When the rotor speed drops to 0, the virtual voltage u of the rotating shaft is estimated. γδ_vir and the estimated rotating shaft system virtual current i γδ_vir The relationship is approximately expressed as:

[0056]

[0057] Where i γ_vir To estimate the virtual current of the γ axis of the rotating axis system, i δ_vir To estimate the virtual current of the δ-axis of the rotating shaft system;

[0058] Because I γ_vir ≈0, then i δ_vir It is expressed as:

[0059]

[0060] In the formula is the estimated value of stator resistance;

[0061] The injection amplitude and stability of the virtual voltage are adjusted by adjusting the injection coefficient of the virtual voltage signal.

[0062] According to the method for generating a virtual voltage signal of a full-order flux observer based on the maximum torque current ratio of the present invention, when the feedback gain coefficient When , the injection coefficient is expressed as m:

[0063]

[0064] Where ξ is the adjustment coefficient.

[0065] Beneficial effects of the present invention: The method of the present invention determines the injected virtual voltage signal by deriving and designing the virtual voltage signal injection coefficient, thereby ensuring the stability of the observer when working at zero speed, and realizing parameter tuning of the motor position observer.

[0066] The method of the present invention is used to achieve the adjustment of the virtual voltage signal injection coefficient based on the full-order flux observer under different load conditions. It constructs the full-order flux observer under the estimated shaft system based on the motor voltage equation under the estimated shaft system; and obtains the mathematical expression relationship between the position estimation error of the full-order flux observer and the virtual voltage signal through the error dynamic equation of the observer and linear decoupling at the local point; at the same time, establishes the relationship between the position estimation error of the position sensorless and the torque of the built-in permanent magnet synchronous motor; and obtains the virtual voltage signal coefficient generation method by setting the position estimation error as the maximum torque-current ratio angle. Compared with the traditional trial-and-error parameter adjustment method, the method of the present invention can adaptively obtain the virtual voltage signal amplitude that needs to be injected according to different load conditions, which has practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 It is a principle block diagram of the method for generating virtual voltage signal of full-order flux observer based on maximum torque current ratio for motor position sensorless vector control according to the present invention; e * is the given speed of the outer speed loop, To estimate the given value of the stator current of the rotating axis δ, To estimate the given value of the stator current of the γ-axis of the rotating shaft system; To estimate the given value of the stator voltage of the rotating shaft system δ axis, To estimate the given value of the stator voltage of the γ-axis of the rotating shaft system, is the given value of the voltage of the α-axis of the stationary shaft system, is the given value of the β-axis voltage of the stationary shaft system, t d is the dead time, i a is the current value of phase a, i c is the c-phase current value, i α is the α-axis current of the stationary shaft system, i β is the β-axis current of the stationary shaft system, u αβ is the static shaft voltage, i αβ is the stationary shaft current;

[0068] Figure 2 Schematic diagram of the reference coordinate system of the method for generating a virtual voltage signal of a full-order flux observer based on the maximum torque current ratio of the present invention; wherein 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; ω e Indicates the true value of electrical angular velocity;

[0069] Figure 3 It is the overall control block diagram of the method for generating virtual voltage signal of full-order flux observer based on maximum torque current ratio according to the present invention; C1 in the figure is the projection coefficient, C1=[0 1] T ;u α is the voltage of the α-axis of the stationary shaft system, u β Static axis β-axis voltage, T a is the switching time of phase a, T b is the switching time of phase b, T c is the switching time of phase c, i b is the current value of phase b;

[0070] Figure 4 is the position estimation error diagram without injecting virtual voltage signal under light load condition;

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

[0072] Figure 6 is the position estimation error diagram without injecting virtual voltage signal under heavy load condition;

[0073] Figure 7 It is a position estimation error diagram based on the method of the present invention under heavy load conditions. DETAILED DESCRIPTION

[0074] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0075] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0076] The present invention will be further described below in conjunction with the accompanying drawings, but is not intended to be a limitation of the present invention.

[0077] Specific implementation method 1. Combination Figures 1 to 3As shown, the present invention provides a method for generating a virtual voltage signal of a full-order flux observer based on a maximum torque current ratio, comprising:

[0078] A full-order flux observer is constructed based on the estimated voltage equation of the interior permanent magnet synchronous motor under the rotating shaft system.

[0079] Linearizing and decoupling the flux error dynamic equation of the full-order flux observer at a local point to obtain a mathematical expression relationship between the position estimation error of the full-order flux observer and the virtual voltage signal;

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

[0081] The position estimation error is set as 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 motor position sensorless vector control, the virtual voltage signal is adjusted based on the injection coefficient of the virtual voltage signal, and the full-order flux observer is used to observe the rotor position and rotor speed at zero speed to obtain rotor position observation values ​​and rotor speed observation values; the rotor position observation values ​​and rotor speed observation values ​​are fed back to a double closed-loop control system to achieve position sensorless vector control of the motor at zero speed.

[0084] In this implementation, 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 working conditions.

[0085] Combination Figures 1 to 3 To further illustrate this embodiment, Figure 2 The reference coordinate system of the present invention is shown as a schematic diagram. The α-β axis, dq axis and γ-δ axis are respectively the stationary, actual rotating and estimated rotating axis systems. The output position of the observer is defined to be aligned with the γ axis, and the position estimation error is expressed as ω e and are the actual and estimated motor electrical angular velocity, respectively.

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

[0087] Furthermore, the voltage equation of the internal permanent magnet synchronous motor under the rotating shaft system is estimated to be:

[0088]

[0089] Where u γδ To estimate the stator voltage of the rotating shaft, u γδ =[u γ u δ ] T , where u γ To estimate the stator voltage of the rotating axis γ, u δ To estimate the stator voltage of the rotating shaft system δ axis, R s is the stator resistance, i γδ To estimate the stator current of the rotating shaft, i γδ =[i γ i δ ] T ,i γ To estimate the stator current of the γ-axis of the rotating shaft system, i δ To estimate the stator current of the rotating shaft system δ axis, ψ s is the stator flux, is the estimated value of electrical angular velocity, J is an orthogonal matrix;

[0090] ψ s =Li γδ +ψ f =[ψ γ ψ δ ] T ,

[0091] Where L is the inductance matrix, ψ f is the permanent magnet flux vector, ψ f =[ψ f1 0] T , ψ f1 is the permanent magnet flux, ψ γ To estimate the stator flux of the rotating axis γ, ψ δ To estimate the stator flux of the rotating axis δ-axis;

[0092] L=[L d ,0;0,L q ] T ,

[0093] Where L d is the d-axis inductance of the actual rotating axis system, L q is the q-axis inductance of the actual rotating axis system;

[0094] J=[0,-1;1,0].

[0095] The error between the estimated current and the actual current is introduced as the observer feedback term, and the full-order flux observer under the estimated shaft system is expressed as:

[0096]

[0097] In the formula is the estimated value of stator flux, To estimate the stator current of the rotating shaft system, the stator flux estimation value is Inversely, λ is the observer gain matrix, To estimate the rotating shaft current error,

[0098] Where K is the feedback gain matrix, I is the unit matrix, k is the feedback gain coefficient, K=kI.

[0099] The full-order flux observer uses the speed adaptation rate to observe the estimated value of the electrical angular velocity

[0100]

[0101] Where k p is the velocity adaptation rate gain coefficient, ε is the generalized position error, k i is the speed adaptation rate integral coefficient, t is the time;

[0102]

[0103] Where W0 is the generalized error projection vector, is the estimated value of the q-axis inductance of the actual rotating axis system, To estimate the stator current of the rotating shaft system δ axis;

[0104]

[0105] In the formula is the estimated value of permanent magnet flux linkage, and σ is the bandwidth coefficient.

[0106] Furthermore, the dynamic equation of the flux error of the full-order flux observer is expressed as:

[0107]

[0108] In the formula is the flux estimation error,

[0109] In this implementation, the flux error dynamic equation of the full-order flux observer is linearized and decoupled at a local point to obtain the linearized flux error dynamic equation of the observer:

[0110]

[0111] The variables with subscript 0 in the formula represent the corresponding variable values ​​at the steady-state operating point; ψ γδ0 To estimate the stator flux at the steady-state operating point of the rotating shaft system, is the position estimation error, θ e is the true position of the rotor, Estimate the position for the rotor;

[0112]

[0113] In the formula is the estimated value of the d-axis inductance of the actual rotating axis system;

[0114] After injecting the virtual voltage signal, the linearized flux estimation error dynamic equation of the full-order flux observer is:

[0115]

[0116] Where u γδ_vir To estimate the virtual voltage of the rotating shaft system;

[0117] When the system is at a steady-state operating point, the generalized position error ε converges to 0; the position estimation error of the full-order flux observer is decoupled from the estimated rotating shaft virtual voltage u γδ_vir The mathematical expression of the relationship is:

[0118]

[0119] Where s is a complex variable in the frequency domain;

[0120] Simplifying formula (6), we get:

[0121]

[0122] Where u γ_vir To estimate the virtual voltage of the γ axis under the rotating axis system, u δ_virTo estimate the virtual voltage of the δ-axis under the rotating shaft system.

[0123] Furthermore, the relationship between the position estimation error and the torque of the built-in permanent magnet synchronous motor is established as follows:

[0124]

[0125] Where T e is the torque, I s is the current amplitude at the motor operating point.

[0126] By combining the relationship between the position estimation error and the 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

[0127]

[0128] In this embodiment, the position estimation error is set The maximum torque current ratio angle is expressed as

[0129] When the rotor speed drops to 0, the virtual voltage u of the rotating shaft is estimated. γδ_vir and the estimated rotating shaft system virtual current i γδ_vir The relationship is approximately expressed as:

[0130]

[0131] Where i γ_vir To estimate the virtual current of the γ axis of the rotating axis system, i δ_vir To estimate the virtual current of the δ-axis of the rotating shaft system;

[0132] Because I γ_vir ≈0, then i δ_vir It is expressed as:

[0133]

[0134] In the formula is the estimated value of stator resistance;

[0135] The injection amplitude and stability of the virtual voltage are adjusted by adjusting the injection coefficient of the virtual voltage signal.

[0136] The virtual voltage injection amplitude and stability of the system can be adjusted by adjusting the virtual injection coefficient m. When , the injection coefficient is expressed as m:

[0137]

[0138] Where ξ is the adjustment coefficient.

[0139] Finally, the full-order flux observer is combined with the virtual voltage signal coefficient generation method to observe the rotor position and speed at zero speed; the rotor position observation values ​​and speed observation values ​​are fed back to the dual closed-loop control system to realize position sensorless vector control of the motor.

[0140] Verification test:

[0141] This experiment was verified on a permanent magnet synchronous motor towing test platform. The 2.2kW built-in permanent magnet synchronous motor and the induction motor were coaxially connected through a coupling, where the built-in permanent magnet synchronous motor was used as the control motor and the induction motor was used as the loading motor. The two inverters were connected in a common DC bus mode. The vector control algorithm was implemented through the STM32F103VCT6 ARM to control the permanent magnet assisted synchronous reluctance motor. The inverter switching frequency was 6kHz.

[0142] 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.

[0143] like Figures 4 to 7 The figure shows the experimental results before and after the virtual voltage signal is injected under light load and full load. The motor load is set to 10% of the rated load and rated load, and the motor is decelerated from 200r / min to zero speed. Figure 4 and Figure 6 It can be observed that if the virtual voltage signal is not injected, when the motor runs near zero speed, the observer position estimation error will diverge quickly, causing the motor to lose control and eventually trigger the overcurrent protection. Figure 5 and Figure 7 It can be observed that when the injection of virtual voltage signal is enabled, the observer can stabilize and stop at zero speed.

[0144] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio, characterized in that: A full-order flux observer is constructed based on the estimated voltage equation of the interior permanent magnet synchronous motor under the rotating shaft system. Linearizing and decoupling the flux error dynamic equation of the full-order flux observer at a local point to obtain a mathematical expression relationship between the position estimation error of the full-order flux observer and the virtual voltage signal; Then, a relationship between the position estimation error and the torque of the built-in permanent magnet synchronous motor is established; The position estimation error is set as 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.

2. The method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio according to claim 1, characterized in that: The estimated voltage equation of the interior permanent magnet synchronous motor under the rotating shaft system is: Where u γδ To estimate the stator voltage of the rotating shaft, u γδ =[u γ u δ ] T , where u γ To estimate the stator voltage of the rotating axis γ, u δ To estimate the stator voltage of the rotating shaft system δ axis, R s is the stator resistance, i γδ To estimate the stator current of the rotating shaft, i γδ =[i γ i δ ] T ,i γ To estimate the stator current of the γ-axis of the rotating shaft system, i δ To estimate the stator current of the rotating shaft system δ axis, ψ s is the stator flux, is the estimated value of electrical angular velocity, J is an orthogonal matrix; ψ s =It γδ +ψ f =[ψ γ ψ δ ] T , Where L is the inductance matrix, ψ f is the permanent magnet flux vector, ψ f =[ψ f1 0] T , ψ f1 is the permanent magnet flux, ψ γ To estimate the stator flux of the rotating axis γ, ψ δ To estimate the stator flux of the rotating axis δ-axis; L=[L d ,0;0,L q ] T , Where L d is the d-axis inductance of the actual rotating axis system, L q is the q-axis inductance of the actual rotating axis system; J＝[0,-1；1,0]。 3. The method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio according to claim 2, characterized in that: The full-order flux observer is expressed as: In the formula is the estimated value of stator flux, To estimate the stator current of the rotating shaft, λ is the observer gain matrix, To estimate the rotating shaft current error, Where K is the feedback gain matrix, I is the unit matrix, k is the feedback gain coefficient, K=kI.

4. The method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio according to claim 3, characterized in that: The full-order flux observer uses the speed adaptation rate to observe the estimated value of the electrical angular velocity Where k p is the velocity adaptation rate gain coefficient, ε is the generalized position error, k i is the speed adaptation rate integral coefficient, t is the time; Where W0 is the generalized error projection vector, is the estimated value of the q-axis inductance of the actual rotating axis system, To estimate the stator current of the rotating shaft system δ axis; In the formula is the estimated value of permanent magnet flux linkage, and σ is the bandwidth coefficient.

5. The method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio according to claim 4, characterized in that: The dynamic equation of flux error of the full-order flux observer is expressed as: In the formula is the flux estimation error, 6. The method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio according to claim 5, characterized in that: The flux error dynamic equation of the full-order flux observer is linearized and decoupled at a local point to obtain: The variables with subscript 0 in the formula represent the corresponding variable values ​​at the steady-state operating point; ψ γδ0 To estimate the stator flux at the steady-state operating point of the rotating shaft system, is the position estimation error, θ e is the true position of the rotor, Estimate the position for the rotor; In the formula is the estimated value of the d-axis inductance of the actual rotating axis system; After injecting the virtual voltage signal, the linearized flux estimation error dynamic equation of the full-order flux observer is: Where u γδ_vir To estimate the virtual voltage of the rotating shaft system; When the system is at a steady-state operating point, the generalized position error ε converges to 0; the position estimation error of the full-order flux observer is decoupled from the estimated rotating shaft virtual voltage u γδ_vir The mathematical expression of the relationship is: Where s is a complex variable in the frequency domain; Simplifying formula (6), we get: Where u γ_vir To estimate the virtual voltage of the γ axis under the rotating axis system, u δ_vir To estimate the virtual voltage of the δ-axis under the rotating shaft system.

7. The method for generating a virtual voltage signal of a full-order flux observer based on 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: Where T e is the torque, I s is the current amplitude at the motor operating point.

8. The method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio according to claim 7, characterized in that: The maximum torque current ratio angle is expressed as 9. The method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio according to claim 8, characterized in that: Set the position estimation error The maximum torque current ratio angle is expressed as When the rotor speed drops to 0, the virtual voltage u of the rotating shaft is estimated. γδ_vir and the estimated rotating shaft system virtual current i γδ_vir The relationship is approximately expressed as: Where i γ_vir To estimate the virtual current of the γ axis of the rotating axis system, i δ_vir To estimate the virtual current of the δ-axis of the rotating shaft system; Because I γ_vir ≈0, then i δ_vir It is expressed as: In the formula is the estimated value of stator resistance; The injection amplitude and stability of the virtual voltage are adjusted by adjusting the injection coefficient of the virtual voltage signal.

10. The method for generating a virtual voltage signal of a full-order flux observer based on maximum torque current ratio according to claim 9, characterized in that: When the feedback gain coefficient When , the injection coefficient is expressed as m: Where ξ is the adjustment coefficient.

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