CN106026834A - Speed sensorless control method of permanent magnet synchronous motor - Google Patents

Abstract

The invention discloses a speed sensorless control method of a permanent magnet synchronous motor in the field of permanent magnet motors, which is based on a conventional assumed rotating coordinate method, combined with a model motor method, and uses a sliding mode control method to directly use the estimated rotational speed as a control quantity, Then the adaptive law of the estimated speed is obtained through the Lyapunov nonlinear design method, which greatly simplifies the algorithm, improves the fast response speed of the system, and can realize the positive and negative rotation of the motor at the same time, which can be used in the permanent magnet synchronous motor.

Description

A speed sensorless control method for permanent magnet synchronous motor

technical field

The invention relates to a permanent magnet motor, in particular to a permanent magnet synchronous motor.

Background technique

In the high-performance permanent magnet synchronous motor servo system, it is usually necessary to install a speed sensor to feed back the speed signal, so as to realize closed-loop control. However, as the requirements for control accuracy become higher and higher, problems such as increased cost, difficult installation, larger system size, and inability to adapt to harsh environments brought about by the use of speed sensors have greatly restricted the application of permanent magnet synchronous motors.

So far, researchers around the world have proposed many speed sensorless control methods, most of which are based on the mathematical model of the motor to design the identification algorithm. The algorithm is complex, the calculation is large, and the forward and reverse control of the motor cannot be realized. The influence of the dead time of the power electronic inverter on the estimation algorithm is not considered.

Contents of the invention

The purpose of the present invention is to provide a speed sensorless control method of a permanent magnet synchronous motor, which improves the detection accuracy of the permanent magnet synchronous motor.

The object of the present invention is achieved like this: a kind of speed sensorless control method of permanent magnet synchronous motor, comprises the following steps:

1) Collect the A-phase and B-phase currents of the motor stator and the DC bus voltage of the inverter, and calculate the corresponding C-phase current;

2) Perform Clark transformation on the A-phase, B-phase and C-phase currents to obtain the α-axis component and β-axis component of the permanent magnet synchronous motor stator current in the αβ coordinate system;

3) Establish an adaptive sliding mode observer based on the rotating coordinate system;

4) Utilize the formula (1) to obtain the adaptive law of the estimated rotational speed of the motor considering the dead zone;

in, is the current error, R _s is the stator phase resistance of the motor, L _s is the synchronous inductance of the motor, ψ _f is the rotor excitation flux linkage, k is the sliding mode gain, _ki is the coefficient of the integral term of the current observation error, sig(x) is the sigmoid function , Δu _q is the q-axis component of the motor stator three-phase voltage lost due to the dead zone in the dq coordinate system;

5) obtain the estimated value of the rotor position angle of the motor to the estimated rotational speed integral obtained by formula (1);

6) Subtract the speed setting value from the estimated speed to obtain the difference of the motor speed, and use it as the input of the PI controller of the speed outer loop to obtain the d-axis component and q-axis component of the motor stator current in the dq coordinate system set value;

7) Using the estimated value of the motor rotor position angle, the α-axis component and β-axis component of the motor stator current in the αβ coordinate system are subjected to Park transformation, and the actual values of the d-axis component and q-axis component of the motor stator current in the dq coordinate system are obtained. value;

8) Perform low-pass filtering on the actual values of the d-axis component and q-axis component of the stator current of the motor in the dq coordinate system, perform Park inverse transformation and Clark inverse transformation, and obtain the filtered A-phase, B-phase and C-phase currents;

9) Judging the current polarity of the filtered A-phase, B-phase and C-phase currents, and obtaining the stator three-phase voltage lost due to the dead zone according to the current polarity;

10) Carry out Clark transformation and Park transformation to the lost stator three-phase voltage, obtain the d-axis component and the q-axis component of the lost stator three-phase voltage under the dq coordinate system;

11) Use the obtained set value and actual value of the d-axis component and q-axis component of the motor stator current in the dq coordinate system as the input of the inner loop current controller, and obtain the d-axis component and the actual control quantity in the dq coordinate system q-axis component;

12) Perform Park inverse transformation on the d-axis component and q-axis component of the actual control quantity in the dq coordinate system to obtain the α-axis component and β-axis component of the actual control quantity in the αβ coordinate system;

13) Perform SVPWM on the α-axis component and β-axis component of the actual control quantity in the αβ coordinate system to obtain six PWM signals;

14) Calculate the estimated value of the d-axis component and q-axis component of the motor stator current in the dq coordinate system, return to step 1), and perform loop control.

As a further limitation of the present invention, in step 3), the mathematical model based on the model motor in the rotating coordinate system adaptive sliding mode observer satisfies formula (2);

in, Estimated rotational angular velocity of the rotor; ω _r is the actual rotational angular velocity of the rotor; u _d , u _q are the components of the stator voltage on the d-axis and q-axis; _id and i _q are the components of the actual stator current on the d-axis and q-axis ; ψ _f is the rotor excitation flux linkage; Δθ is the phase difference between the assumed rotating coordinate system where the model motor is located and the dq coordinate system where the actual PMSM is located; R _s is the stator phase of the motor resistance; L _s is the synchronous inductance of the motor; Δu _d and Δu _q are the loss voltage of u _d and u _q caused by the dead zone of the inverter; u is the control value of the model motor, and at the same time, the It can also be regarded as the control quantity of the model motor.

As a further limitation of the present invention, the sigmoid function in step 4) satisfies formula (3);

Among them, a is the sigmoid constant.

As a further limitation of the present invention, the current inner loop controller in step 8) adopts Lyapunov direct method to design, and the selected Lyapunov function satisfies formula (4);

Among them, K _i is the integral coefficient, is the component of the current setting value on the d-axis, is the component of the current setting value on the q-axis.

As a further limitation of the present invention, the stator three-phase voltage of loss in step 9) satisfies formula (5);

Among them, T _d is the dead time, T _s is the PWM wave period, sign(x) is the sign function, i _A , i _B , i _C are the filtered A-phase, B-phase and C-phase currents, u _dc is the inverter DC side bus voltage of the converter.

As a further limitation of the present invention, the sign function satisfies formula (6);

Compared with the prior art, the beneficial effect of the present invention is that the present invention uses the adaptive sliding mode observer based on the rotating coordinate system considering the dead zone to estimate the rotational speed information of the permanent magnet synchronous motor, based on the conventional assumed rotating coordinate method , combined with the current control of the model motor, the sliding mode identification is carried out in the dq coordinate system, and then the adaptive law of the estimated speed is directly obtained by using the Lyapunov nonlinear control design method. The motor current control is carried out using the Lyapunov method to ensure global convergence. In the model motor Considering the voltage change caused by the dead zone of the inverter, the phase identification error in the presence of the dead zone is eliminated, the response speed is fast, and the positive and negative rotation of the motor can be realized, which improves the accuracy of the speed detection. The invention can be used in permanent magnet synchronous motors.

Description of drawings

Fig. 1 is a block diagram of the control principle of the present invention.

Fig. 2 is a control flow chart of the present invention.

Fig. 3 is a curve diagram of the rotational speed when the present invention works.

Fig. 4 is a graph of rotor position angle in the present invention.

detailed description

The present invention will be further described below in conjunction with specific embodiments.

A speed sensorless control method for a permanent magnet synchronous motor, comprising the following steps:

1) Design an adaptive sliding mode observer

Build the actual motor model:

Build an estimated motor model:

in, Estimated rotational angular velocity of the rotor; ω _r is the actual rotational angular velocity of the rotor; u _d , u _q are the components of the stator voltage on the d-axis and q-axis; _id and i _q are the components of the actual stator current on the d-axis and q-axis ; ψ _f is the rotor excitation flux linkage; Δθ is the phase difference between the assumed rotating coordinate system of the model motor and the actual dq coordinate system; R _s is the phase resistance of the motor stator ; L _s is the synchronous inductance of the motor; Δu _d and Δu _q are the loss voltages of u _d and u _q caused by the dead zone of the inverter; u is the control value of the model motor, and at the same time, the It can also be regarded as the control quantity of the model motor.

Subtract formula (2) from formula (1), if the motor parameters in the two formulas are exactly the same, the current error equation is obtained:

in, is the current error,

In order to ensure that the current error in formula (3) is 0, the integral term of the current observation error is introduced, and the Lyapunov function is taken:

In the formula, _ki is the coefficient of the integral term of the current observation error.

Deriving formula (4), we get:

Substituting formula (3) into formula (5), we get:

make:

In the formula, k is the sliding mode gain.

Comparing formula (1) and formula (2), at the same time, it can be known from formula (3) that when the system is stable, and Due to the introduction of the current error integral term, the The average value of u in formula (7) will be equal to 0, thus Δθ=0, the two motors are completely synchronized, at this time, formula (3) satisfies:

Therefore, the adaptive law of the estimated rotational speed can be obtained from formula (8):

Then, the estimated rotor position angle is:

2) Design the current inner loop controller

The goal of the whole control system is to make converges to the set value i _d ^* , Converge to the set value i _q ^* , in order to eliminate the steady-state error, the error integral term is introduced, so the Lyapunov function is defined:

It can be seen from formula (2) that if the and used to control the and The state equation contains the control quantity, and the control quantity adopts sliding mode control, so chattering is bound to be introduced into the controller, which will affect the stability of the controller.

However, once the model motor and the actual PMSM are fully synchronized, i.e. is exactly the same as i _d and i _q , then, the can be replaced by the actual i _d and i _q , therefore, the Lyapunov function defined in formula (12) becomes:

Among them, K _i is the integral coefficient, is the component of the current setting value on the d-axis, is the component of the current setting value on the q-axis.

Deriving formula (13), we get:

Since the two motors are fully synchronized, there is Δθ=0, Therefore, formula (1) becomes:

Substituting formula (15) into formula (14), we get:

make:

Among them, K _p is the proportional coefficient.

Then, formula (14) becomes:

Obviously, when x≠0, Stability in the Lyapunov sense is satisfied. At the same time, the actual control law can be obtained by transforming the formula (17):

The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solutions disclosed in the present invention, those skilled in the art can make some replacements and modifications to some of the technical features according to the disclosed technical content without creative work. Deformation, these replacements and deformations are all within the protection scope of the present invention.

Claims (6)

1. a speed sensorless control method of permanent magnet synchronous motor, is characterized in that, comprises the following steps: 1) Collect the A-phase and B-phase currents of the motor stator and the DC bus voltage of the inverter, and calculate the corresponding C-phase current; 2) Perform Clark transformation on the A-phase, B-phase and C-phase currents to obtain the α-axis component and β-axis component of the permanent magnet synchronous motor stator current in the αβ coordinate system; 3) Establish an adaptive sliding mode observer based on the rotating coordinate system; 4) Utilize the formula (1) to obtain the adaptive law of the estimated rotational speed of the motor considering the dead zone; ${\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\stackrel{<span\; class="notranslate">\; ~</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Integral;</span>{\stackrel{<span\; class="notranslate">\; ~</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; q</span>}}\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; (</span>{\stackrel{<span\; class="notranslate">\; ~</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}}{{\mathrm{<span\; class="notranslate">\; \&psi;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\stackrel{<span\; class="notranslate">\; ~</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ in, is the current error, i _d and i _q are the components of the actual stator current on the d-axis and q-axis; is the component of the stator estimated current on the d-axis and q-axis, R _s is the stator phase resistance of the motor, L _s is the synchronous inductance of the motor, ψ _f is the rotor excitation flux linkage, k is the sliding mode gain, and _ki is the current observation error integral Term coefficient, sig(x) is a sigmoid function, Δu _q is the q-axis component of the motor stator three-phase voltage lost due to the dead zone in the dq coordinate system; 5) obtain the estimated value of the rotor position angle of the motor to the estimated rotational speed integral obtained by formula (1); 6) Subtract the speed setting value from the estimated speed to obtain the difference of the motor speed, and use it as the input of the PI controller of the speed outer loop to obtain the d-axis component and q-axis component of the motor stator current in the dq coordinate system set value; 7) Using the estimated value of the motor rotor position angle, the α-axis component and β-axis component of the motor stator current in the αβ coordinate system are subjected to Park transformation, and the actual values of the d-axis component and q-axis component of the motor stator current in the dq coordinate system are obtained. value; 8) Perform low-pass filtering on the actual values of the d-axis component and q-axis component of the stator current of the motor in the dq coordinate system, perform Park inverse transformation and Clark inverse transformation, and obtain the filtered A-phase, B-phase and C-phase currents; 9) Judging the current polarity of the filtered A-phase, B-phase and C-phase currents, and obtaining the stator three-phase voltage lost due to the dead zone according to the current polarity; 10) Carry out Clark transformation and Park transformation to the lost stator three-phase voltage, obtain the d-axis component and the q-axis component of the lost stator three-phase voltage under the dq coordinate system; 11) Use the obtained set value and actual value of the d-axis component and q-axis component of the motor stator current in the dq coordinate system as the input of the inner loop current controller, and obtain the d-axis component and the actual control quantity in the dq coordinate system q-axis component; 12) Perform Park inverse transformation on the d-axis component and q-axis component of the actual control quantity in the dq coordinate system to obtain the α-axis component and β-axis component of the actual control quantity in the αβ coordinate system; 13) Perform SVPWM on the α-axis component and β-axis component of the actual control quantity in the αβ coordinate system to obtain six PWM signals; 14) Calculate the estimated value of the d-axis component and q-axis component of the motor stator current in the dq coordinate system, return to step 1), and perform loop control. 2. the speed sensorless control method of a kind of permanent magnet synchronous motor according to claim 1, is characterized in that, in step 3) based on the mathematical model of the model motor in the rotating coordinate system adaptive sliding mode observer satisfies formula ( 2); $\left\{\begin{array}{c}\frac{\mathrm{<span\; class="notranslate">\; d</span>}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; +</span>{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}}_{\mathrm{<span\; class="notranslate">\; r</span>}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; u</span>}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; \&Delta;u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}\\ \frac{\mathrm{<span\; class="notranslate">\; d</span>}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; q</span>}}}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; -</span>\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; -</span>{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}}_{\mathrm{<span\; class="notranslate">\; r</span>}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\stackrel{<span\; class="notranslate">\; ^</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}}_{\mathrm{<span\; class="notranslate">\; r</span>}}{\mathrm{<span\; class="notranslate">\; \&psi;</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; -</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; \&Delta;\; u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ in, Estimated rotational angular velocity of the rotor; ω _r is the actual rotational angular velocity of the rotor; u _d , u _q are the components of the stator voltage on the d-axis and q-axis; _id and i _q are the components of the actual stator current on the d-axis and q-axis ; ψ _f is the rotor excitation flux linkage; Δθ is the phase difference between the assumed rotating coordinate system where the model motor is located and the dq coordinate system where the actual PMSM is located; R _s is the stator phase of the motor resistance; L _s is the synchronous inductance of the motor; Δu _d and Δu _q are the loss voltage of u _d and u _q caused by the dead zone of the inverter; u is the control value of the model motor, and at the same time, the It can also be regarded as the control quantity of the model motor. 3. the speed sensorless control method of a kind of permanent magnet synchronous motor according to claim 1 or 2, is characterized in that, the sigmoid function in step 4) satisfies formula (3); $\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; x</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$ Among them, a is the sigmoid constant. 4. the speed sensorless control method of a kind of permanent magnet synchronous motor according to claim 1 or 2, is characterized in that, the current inner loop controller in step 8) adopts Lyapunov direct method to design, and the selected Lyapunov function Satisfy the formula (4); $\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{<span\; class="notranslate">\; \&lsqb;</span><span\; class="notranslate">\; \&Integral;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; \&rsqb;</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{<span\; class="notranslate">\; \&lsqb;</span><span\; class="notranslate">\; \&Integral;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; \&rsqb;</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$ Among them, K _i is the integral coefficient, is the component of the current setting value on the d-axis, for current Sets the component of the value on the q-axis. 5. the speed sensorless control method of a kind of permanent magnet synchronous motor according to claim 1 or 2, is characterized in that, the stator three-phase voltage of loss in step 9) satisfies formula (5); $\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; \&Delta;u</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; g</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; A</span>}}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; \&Delta;u</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; g</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; B</span>}}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; \&Delta;u</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; c</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; g</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; )</span>\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$ Among them, T _d is the dead time, T _s is the PWM wave period, sign(x) is the sign function, i _A , i _B , i _C are the filtered A-phase, B-phase and C-phase currents, u _dc is the inverter DC side bus voltage of the converter. 6. the speed sensorless control method of a kind of permanent magnet synchronous motor according to claim 5, is characterized in that, sign function satisfies formula (6); $\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; g</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}& \mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; .</span>$