Construction method of permanent magnet motor full-order state observer based on virtual voltage signal injection

Abstract

The application discloses a full-order state observer method for an interior permanent magnet synchronous motor based on virtual voltage signal injection and belongs to the technical field of motor position sensorless control. The application aims at the problem that the existing state observer method based on a motor fundamental model cannot run at zero speed of the motor. The application comprises the following steps: establishing an initial full-order state observer based on an estimated rotating shaft system voltage equation of the interior permanent magnet synchronous motor; establishing a nonlinear equation group of the interior permanent magnet synchronous motor in a stationary shaft system and calculating a Lie derivative matrix of motor system state variables; deducing a zero-speed local weak-observability criterion of the initial full-order state observer; constructing an observer voltage input model at zero speed by using the criterion; and updating the initial full-order state observer to obtain an updated full-order state observer which is used for state observation of the interior permanent magnet synchronous motor at zero synchronous speed. The application can realize estimation of the rotor position at zero synchronous speed.

Description

Technical Field

[0001] This invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection, belonging to the field of sensorless motor control technology. Background Technology

[0002] With the development of industrial electrification, electric motors, as core equipment in industrial manufacturing and energy conversion, have received widespread attention. Among them, built-in permanent magnet synchronous motors, due to their high power density and high reliability, have been widely used in intelligent manufacturing, transportation, and other fields. To further improve the reliability of motor systems and reduce system costs, sensorless control schemes have attracted widespread attention. At the same time, in some industrial applications, the ability of motor systems to operate stably under heavy load at zero speed is required. Therefore, position and speed observation technology at zero speed is very important.

[0003] Sensorless control methods can be mainly divided into two categories: the motor fundamental wave model method and the high-frequency signal injection method. The high-frequency injection method exhibits good performance at zero and low speeds, but injecting high-frequency signals inevitably introduces high-frequency noise and vibration, which is unacceptable in some situations. However, the motor fundamental wave model method is difficult to use under zero-low-speed heavy-load operating conditions, a consensus widely held in academia. The main reasons for the instability of the model method under zero-low-speed operating conditions are the existence of unstable poles in the observer at zero and low speeds and the unobservability of the motor system at zero speed.

[0004] To extend the operational limit of the model method and enable its operation at zero speed, numerous approaches have emerged in the past decade or so. These approaches can be summarized as injecting bias current into the d-axis of the motor and methods based on optimized observer structures. However, none of these methods currently achieve stable operation at zero speed. Therefore, a built-in permanent magnet synchronous motor position observer based on the motor's fundamental wave model, suitable for zero speed operation, is of great significance. Summary of the Invention

[0005] To address the problem that existing state observation methods based on the fundamental wave model of a motor cannot operate at zero speed, this invention provides a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0006] The present invention provides a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection, comprising:

[0007] An initial full-order state observer is established based on the estimated voltage equations of the built-in permanent magnet synchronous motor in the rotating shaft system;

[0008] A set of nonlinear equations for a built-in permanent magnet synchronous motor in a stationary shaft system is established. The Lie derivative matrix of the motor system state variables is calculated using the set of nonlinear equations. Then, the zero-velocity local weak energy observability criterion of the initial full-order state observer is derived based on the determinant of the Lie derivative matrix.

[0009] A zero-speed local weak observability criterion is used to construct a zero-speed observer voltage input model; then, the initial full-order state observer is updated based on the zero-speed observer voltage input model to obtain an updated full-order state observer, which is used for state observation of the built-in permanent magnet synchronous motor at zero synchronous speed.

[0010] The present invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0011] The voltage equation for 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 linkage. 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] The present invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0020] The initial full-order state observer is:

[0021] (2),

[0022] 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, ;

[0023] ,

[0024] In the formula For the feedback gain matrix, It is the identity matrix. K = kI, which is the feedback gain coefficient.

[0025] The present invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0026] The initial full-order state observer uses the velocity adaptive rate to observe the electric angular velocity estimate. :

[0027] (3),

[0028] In the formula For the speed adaptive rate gain coefficient, For generalized position error, The integral coefficient of the speed adaptive rate, For time;

[0029] ,

[0030] 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;

[0031] , ,

[0032] In the formula This is an estimate of the flux linkage of the permanent magnet. This is the bandwidth factor;

[0033] The velocity adaptive rate is achieved by adjusting the generalized position error. Reaching 0 achieves the estimated value of electric angular velocity. Tracking.

[0034] According to the method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection according to the present invention, the nonlinear equation set of the embedded permanent magnet synchronous motor in the stationary shaft system is as follows:

[0035] (4)

[0036] In the formula For the α-axis current of the stationary axis, The voltage across the α-axis of the stationary axis system. For the average inductance of the actual rotating shaft system, L0 = (L d +L q ) / 2; For the actual rotating shaft differential inductance, L1 = (L d -L q ) / 2; This is the actual angle of the rotor. The voltage across the β-axis of the stationary axis system. For the β-axis current of the stationary axis, This is the true value of the electric angular velocity;

[0037] The nonlinear equation system can be simplified as follows:

[0038] (5),

[0039] In the formula For the state variables of the motor system, ; Input variables to the system, ; For input nonlinear functions, ; Output variables for the system; To output a nonlinear function, , = , = .

[0040] The present invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0041] The Lie derivative matrix of the state variables of the motor system is expressed as: :

[0042] (6),

[0043] In the formula for With respect to the k-th Lie derivative of the input nonlinear function f, i=1,2; k=0,1.

[0044] The present invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0045] According to the Lie derivative matrix The determinant derivation of the zero-velocity local weak observability criterion for the initial full-order state observer is as follows:

[0046] (7),

[0047] In the formula This serves as a criterion for local weak observability at zero velocity.

[0048] Transforming formula (7) into the actual rotating axis system, it can be expressed as:

[0049] (8),

[0050] In the formula This represents the q-axis voltage of the actual rotating shaft system. This represents the q-axis current of the actual rotating shaft system.

[0051] The present invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0052] Using the zero-velocity local weak energy observability criterion Construct the observer voltage input model at zero velocity:

[0053] (9),

[0054] In the formula Input variables for the updated system. To estimate the virtual voltage injected into the observer along the γ-axis of the rotating shaft system, To estimate the virtual voltage injected into the observer along the delta axis of the rotating shaft system, The coefficients for virtual voltage injection.

[0055] The present invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0056] The zero-velocity local weak observability criterion is obtained from the zero-velocity observer voltage input model. for:

[0057] (10).

[0058] The present invention relates to a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection.

[0059] Based on the zero-velocity local weak energy observation criterion The initial full-order state observer is updated to obtain the updated full-order state observer as follows:

[0060] (11),

[0061] In the formula , To estimate the composite virtual voltage of the rotating shaft system.

[0062] The beneficial effects of this invention are as follows: This invention is used for rotor position estimation of motors. Compared with the traditional sensorless estimation method for permanent magnet synchronous motors at zero speed, the full-order state observer based on virtual voltage signal injection designed in this invention can estimate the rotor position at zero synchronous speed. At the same time, it does not require the injection of additional real signals to ensure observation stability, reduces operating noise, and enhances the practical value of the built-in permanent magnet synchronous motor position observer technology based on the motor fundamental wave model.

[0063] This invention provides a method for zero-speed position observation of an embedded permanent magnet synchronous motor based on a fundamental motor model. This method significantly expands the application scenarios and scope of sensorless systems based on observing the fundamental motor model. Furthermore, this observation method ensures position error convergence and stable operation at zero speed. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the reference coordinate system for the method of constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection as described in this invention; the figure shows... Estimate the angle for the rotor. For rotor angle estimation error, ;

[0065] Figure 2 This is a control block diagram of the method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection, as described in this invention; the diagram shows... For projection coefficients, ; 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, i a Let i be the phase current value. b Let i be the phase b current value. c This represents the c-phase current value; Inverter indicates the inverter. To estimate the given value of the stator current of the rotating shaft system γ-axis;

[0066] Figure 3This is a graph showing the experimental results under full load without the injection of a virtual voltage signal;

[0067] Figure 4 This is a graph showing the experimental results of injecting a virtual voltage signal under full load conditions;

[0068] Figure 5 This is a schematic diagram illustrating the application of the method of this invention to rotor position estimation in a permanent magnet synchronous motor; the diagram shows... 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 Dead time, Voltage of the stationary axis It represents the current in the stationary axis system. Detailed Implementation

[0069] 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.

[0070] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0071] The present invention will be further described below with reference to the accompanying drawings, but this should not be construed as limiting the invention.

[0072] Specific Implementation Method 1: Combination Figure 1 and Figure 2 As shown, this invention provides a method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection, comprising:

[0073] An initial full-order state observer is established based on the estimated voltage equation of the built-in permanent magnet synchronous motor in the rotating shaft system to estimate the rotor position of the motor.

[0074] A set of nonlinear equations for a built-in permanent magnet synchronous motor in a stationary shaft system is established. The Lie derivative matrix of the motor system state variables is calculated using the set of nonlinear equations. Then, the zero-velocity local weak energy observability criterion of the initial full-order state observer is derived based on the determinant of the Lie derivative matrix.

[0075] A zero-speed local weak energy observability criterion is used to construct a zero-speed observer voltage input model; then, the initial full-order state observer is updated based on the zero-speed observer voltage input model to obtain an updated full-order state observer, which is used for state observation of the built-in permanent magnet synchronous motor at zero synchronous speed, thus realizing the stable operation of the built-in permanent magnet synchronous motor at zero synchronous speed.

[0076] In this embodiment, the voltage equation of the permanent magnet synchronous motor is analyzed, and a full-order state observer of the built-in permanent magnet synchronous motor based on virtual voltage signal injection is designed to achieve zero-speed operation of the built-in permanent magnet synchronous motor.

[0077] Combination Figure 1 and Figure 2 Define the observer output position alignment axis.

[0078] Figure 2 This includes dual-loop control and a full-order state observer based on virtual voltage signal injection. When the system is in dual-loop vector control, the outer speed loop outputs the current given by comparing the given speed with the estimated speed, while 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 realize motor control. This enables the observation of rotor position and speed information, and completes sensorless closed-loop control using the estimated rotor position and speed information.

[0079] Furthermore, the voltage equation for the built-in permanent magnet synchronous motor under the rotating shaft system is estimated as follows:

[0080] (1),

[0081] 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;

[0082] ,

[0083] In the formula For the inductor matrix, Let be the flux linkage vector of the permanent magnet. , It is a permanent magnet flux linkage. 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;

[0084] ,

[0085] In the formula For the actual rotating shaft system, the d-axis inductance. For the actual rotating shaft system, the q-axis inductance;

[0086] .

[0087] The initial full-order state observer is:

[0088] (2),

[0089] 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, ;

[0090] ,

[0091] In the formula For the feedback gain matrix, It is the identity matrix. K = kI, which is the feedback gain coefficient.

[0092] The initial full-order state observer uses the velocity adaptive rate to observe the electric angular velocity estimate. :

[0093] (3),

[0094] In the formula For the speed adaptive rate gain coefficient, For generalized position error, The integral coefficient of the speed adaptive rate, For time;

[0095] ,

[0096] 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;

[0097] , ,

[0098] In the formula This is an estimate of the flux linkage of the permanent magnet. This is the bandwidth factor;

[0099] The velocity adaptive rate is achieved by adjusting the generalized position error. Reaching 0 achieves the estimated value of electric angular velocity. Precise tracking.

[0100] Furthermore, the nonlinear equations of a stationary permanent magnet synchronous motor with an embedded permanent magnet are as follows:

[0101] (4)

[0102] In the formula For the α-axis current of the stationary axis, The voltage across the α-axis of the stationary axis system. For the average inductance of the actual rotating shaft system, L0 = (L d +L q ) / 2; For the actual rotating shaft differential inductance, L1 = (L d -L q ) / 2; This is the actual angle of the rotor. The voltage across the β-axis of the stationary axis system. For the β-axis current of the stationary axis, This is the true value of the electric angular velocity;

[0103] The nonlinear equation system can be simplified as follows:

[0104] (5),

[0105] In the formula For the state variables of the motor system, ; Input variables to the system, ; For input nonlinear functions, ; Output variables for the system; To output a nonlinear function, , = , = .

[0106] In this embodiment, the Lie derivative matrix of the motor system state variables is represented as follows: :

[0107] (6),

[0108] In the formula for With respect to the k-th Lie derivative of the input nonlinear function f, i=1,2; k=0,1.

[0109] Furthermore, based on the aforementioned Lie derivative matrix The determinant derivation of the zero-velocity local weak observability criterion for the initial full-order state observer is as follows:

[0110] (7),

[0111] In the formula This serves as a criterion for local weak observability at zero velocity.

[0112] Transforming formula (7) into the actual rotating axis system, it can be expressed as:

[0113] (8),

[0114] In the formula This represents the q-axis voltage of the actual rotating shaft system. Let q be the actual q-axis current of the rotating shaft system. If the system satisfies this criterion, then the state variables of the sensorless system become observable again.

[0115] Using the zero-velocity local weak energy observability criterion Construct the observer voltage input model at zero velocity:

[0116] (9),

[0117] In the formula Input variables for the updated system. To estimate the virtual voltage injected into the observer along the γ-axis of the rotating shaft system, To estimate the virtual voltage injected into the observer along the delta axis of the rotating shaft system, The coefficients for virtual voltage injection.

[0118] Because the position estimation error is small, the estimated rotation axis system and the actual rotation axis system can be considered to coincide. At this point, the zero-velocity local weak energy observability criterion can be obtained from the zero-velocity observer voltage input model. for:

[0119] (10).

[0120] It can be observed that the observer's state variables regain local weak observability at zero velocity.

[0121] Finally, based on the zero-velocity local weak energy observability criterion The initial full-order state observer is updated to obtain the updated full-order state observer as follows:

[0122] (11),

[0123] In the formula , To estimate the composite virtual voltage of the rotating shaft system.

[0124] This enables the stable operation of the built-in permanent magnet synchronous motor at zero synchronous speed.

[0125] Verification experiment:

[0126] This experiment was conducted on a permanent magnet assisted synchronous reluctance motor (PMSM) tractor test 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.

[0127] 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.

[0128] Figure 3 and Figure 4 The figure shows the results of a comparative experiment on injecting a virtual voltage signal under full load. The motor load was set to the rated load, and the motor decelerated from 200 r / min to zero speed under load. Figure 3 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 4 It can be observed that when the virtual voltage signal is enabled, the observer can remain stably stationary at zero speed. This demonstrates that the method of this invention can achieve zero-speed operation.

[0129] Figure 5 As shown, the method of the present invention is applied to the estimation of motor rotor position. The system is controlled by a dual closed loop of speed and current, and the position and speed information at zero speed is provided by a full-order state observer based on virtual voltage signal injection.

[0130] 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 state observer for a permanent magnet motor based on virtual voltage signal injection, characterized in that, include: An initial full-order state observer is established based on the estimated voltage equations of the built-in permanent magnet synchronous motor in the rotating shaft system; A set of nonlinear equations for a built-in permanent magnet synchronous motor in a stationary shaft system is established. The Lie derivative matrix of the motor system state variables is calculated using the set of nonlinear equations. Then, the zero-velocity local weak energy observability criterion of the initial full-order state observer is derived based on the determinant of the Lie derivative matrix. A zero-speed local weak observability criterion is used to construct a zero-speed observer voltage input model; then, the initial full-order state observer is updated based on the zero-speed observer voltage input model to obtain an updated full-order state observer, which is used for state observation of the built-in permanent magnet synchronous motor at zero synchronous speed. 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 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; ， In the formula For the inductor matrix, Let be the flux linkage vector of the permanent magnet. , It is a permanent magnet flux linkage. 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 For the actual rotating shaft system, the d-axis inductance. For the actual rotating shaft system, the q-axis inductance; ； The initial full-order state observer is: （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. For the feedback gain coefficient, K = kI; The nonlinear equations of a stationary permanent magnet synchronous motor with an embedded permanent magnet are as follows: （4） In the formula For the α-axis current of the stationary axis, The voltage across the α-axis of the stationary axis system. For the average inductance of the actual rotating shaft system, L0 = (L d +L q ) / 2; For the actual rotating shaft differential inductance, L1 = (L d -L q ) / 2; This is the actual angle of the rotor. The voltage across the β-axis of the stationary axis system. For the β-axis current of the stationary axis, This is the true value of the electric angular velocity; The nonlinear equation system can be simplified as follows: （5）， In the formula For the state variables of the motor system, ; Input variables to the system, ; For input nonlinear functions, ; Output variables for the system; To output a nonlinear function, , = , = ; According to the Lie derivative matrix The determinant derivation of the zero-velocity local weak observability criterion for the initial full-order state observer is as follows: （7）， In the formula This serves as a criterion for local weak observability at zero velocity. Transforming formula (7) into the actual rotating axis system, it can be expressed as: （8）， In the formula This represents the q-axis voltage of the actual rotating shaft system. This refers to the q-axis current of the actual rotating shaft system. Based on the zero-velocity local weak energy observation criterion The initial full-order state observer is updated to obtain the updated full-order state observer as follows: （11）， In the formula , To estimate the composite virtual voltage of the rotating shaft system; The coefficients for virtual voltage injection.

2. The method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection according to claim 1, characterized in that, The initial full-order state observer uses the 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 estimate of the flux linkage of the permanent magnet. This is the bandwidth factor; The velocity adaptive rate is achieved by adjusting the generalized position error. Reaching 0 achieves the estimated value of electric angular velocity. Tracking.

3. The method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection according to claim 2, characterized in that, The Lie derivative matrix of the state variables of the motor system is expressed as: : （6）， In the formula for With respect to the m-th order Lie derivative of the input nonlinear function f, i=1,2; m=0,1.

4. The method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection according to claim 3, characterized in that, Using the zero-velocity local weak energy observability criterion Construct the observer voltage input model at zero velocity: （9）， In the formula Input variables for the updated system. To estimate the virtual voltage injected into the observer along the γ-axis of the rotating shaft system, To estimate the virtual voltage injected into the observer along the delta axis of the rotating shaft system, The coefficients for virtual voltage injection.

5. The method for constructing a full-order state observer for a permanent magnet motor based on virtual voltage signal injection according to claim 4, characterized in that, The zero-velocity local weak observability criterion is obtained from the zero-velocity observer voltage input model. for: （10）。

Images