CN103701386B - Based on the acquisition methods of the full rank flux observer of the Speed Sensorless Induction Motor of observation magnetic linkage error - Google Patents

Abstract

The invention discloses a method for obtaining a full-order flux observer without a speed sensor of an asynchronous motor based on observing flux error, and belongs to the field of full-order flux observers for speed sensorless vector control. It solves the problem that in the existing speed sensorless vector control system, when the motor is running at low speed, due to the large error of the motor parameters, the observation accuracy of the full-order flux observer is low, which eventually leads to poor system operation stability. According to the following criteria, the error feedback matrix coefficients of the full-order flux linkage observer are obtained: the real part of the pole of the observer is smaller than the real part of the pole of the asynchronous motor, and both are negative numbers, and the real parts of the zero and pole points of the estimated speed transfer function are all negative numbers, using the estimated flux linkage and The error of the real flux linkage ensures that the system is equivalent to a current model when the motor is running at low speed, and is equivalent to a voltage model when the system motor is running at high speed. Using the rotor flux phase error coefficient i _λ and introducing the rotor flux magnitude error coefficient k to increase the accuracy of the estimated speed. It is specifically used in the field of speed sensorless vector control.

Description

Acquisition method of full-order flux observer without speed sensor for asynchronous motor based on observed flux error

technical field

The invention belongs to the field of a speed sensorless vector control full-order flux linkage observer.

Background technique

Asynchronous motor vector control technology can realize the decoupling of torque and flux linkage, and has good dynamic characteristics and steady-state characteristics, so it has been widely used in industrial systems. In many industrial occasions, motors are required to run stably in low-speed areas, such as hoists, winches, excavators, etc., but because the speed sensors required for control are expensive and easily damaged, the reliability of the speed control system is reduced. Increased maintenance costs. However, when the speed sensorless vector control system is running at low speed, due to the large error of the motor parameters, it is easy to cause the system to run unstable. To sum up, in order to avoid the use of speed sensors and enhance the service life of the system, it is necessary to study the low-speed stable operation scheme of the speed sensorless vector control.

According to the observer principle, the speed sensorless vector control uses the state equations composed of the dynamic model of the asynchronous motor to estimate the flux linkage of the stator and the rotor, and introduces error feedback to improve the observation accuracy of the state variables. Since the observer contains rotor speed variable information, the speed adaptive law can be designed according to the observer principle to observe the rotor speed. However, the accuracy of flux linkage observation and speed observation accuracy are closely related to the motor parameters. When the motor parameters are inaccurate, it will have a great impact on the stable operation of the motor, especially when the motor is running at low speed. When the motor is running at medium and high speeds, the back electromotive force of the motor is very large, so the influence of the parameters on the control system is relatively small, and the sensorless vector control system can maintain stable operation. But when the motor is running at low speed (below 30rpm), the back electromotive force of the motor is small, and the influence of the motor parameters becomes greater. If the parameters are inaccurate, the estimation of the flux linkage and rotor speed will be inaccurate, resulting in control failure. It is impossible to obtain the parameters of asynchronous motor accurately in actual work, and when the motor runs for a long time, the motor parameters will also change greatly, so when the motor is controlled at low speed and very low speed (below 15rpm), it can achieve good speed accuracy and Stability is somewhat difficult.

Judging from the existing speed sensorless vector control technology, the observation methods of flux linkage are mainly divided into the following two types: 1) Open-loop flux linkage observation. Open-loop flux linkage observation is a flux linkage calculation method based on the motor dynamic equation, which can be divided into voltage model method, current model method and open-loop full-order flux linkage observer. The voltage model method is not applicable because it includes stator resistance parameters. Same as when the motor is running at low speed, the current model is not applicable when the motor is running at high speed. However, the open-loop full-order flux observer has poor system robustness because it has no error feedback compensation term. 2) Closed-loop flux linkage observation. Compared with the open-loop flux observation system, the closed-loop flux observation system introduces an error feedback item, which improves the robustness of the system. It can be divided into model reference adaptive, closed-loop full-order flux observer, closed-loop reduced-order flux observer and Kalman filter method. At present, the closed-loop full-order flux observer is widely used. For this method, the main problems to be solved are the accuracy of flux linkage observation and the stability of the system, which need to be satisfied by designing the error feedback matrix and the speed adaptive law reasonably. However, in the prior art, only the error feedback matrix is designed to meet the accuracy requirements of the observed flux linkage or the system stability requirements. A design method that can satisfy both requirements has not been reported yet.

Contents of the invention

The present invention aims to solve the problem that in the existing speed sensorless vector control system when the motor is running at low speed, the observation accuracy of the full-order flux observer is low due to the large error of the motor parameters, which ultimately leads to poor system operation stability. A method for obtaining a full-order flux observer without a speed sensor of an asynchronous motor based on observing the flux error is provided.

A method for obtaining a full-order flux observer without a speed sensor for an asynchronous motor based on observing flux linkage errors, the method is realized based on an existing full-order flux observer, and it is characterized in that the method includes the following steps,

Step 1. When the following three conditions are met, obtain 4 error feedback coefficients, and the 4 error feedback coefficients are g ₁ , g ₂ , g ₃ and g ₄ respectively, and substitute the obtained 4 error feedback coefficients into

$G={\left[\begin{array}{cccc}{g}_1& {-g}_2& g_3& {-g}_4\\ g_2& g_1& g_4& g_3\end{array}\right]}^T$ (Formula 1)

In, get G,

Among them, G represents the error feedback matrix of the observer,

The three conditions are,

Condition 1: The real part of the pole of the observer is smaller than the real part of the pole of the asynchronous motor, and both are negative numbers,

Condition 2: The real parts of the poles and zeros of the estimated speed transfer function are all negative numbers,

Condition 3: Use the error between the estimated flux linkage and the real flux linkage to ensure that the system is equivalent to a current model when the motor is running at low speed, and the system is equivalent to a voltage model when the motor is running at high speed;

Step 2. According to the known rotational speed adaptive law equation:

${\widehat{\mathrm{\ω}}}_r=k_1(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})-k_2(e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})$ (Formula 2),

Obtain the adaptive law equation of the rotational speed after deformation

${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(i_{\mathrm{sq}}-{\hat{i}}_{\mathrm{sq}}){\widehat{\mathrm{\λ}}}_{\mathrm{rd}}+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}]$ (Formula 3),

in, represents the estimated motor speed,

k ₁ represents the stator current error gain,

e _iα represents the error component of the horizontal axis in the stationary coordinate system between the estimated stator current and the actual stator current,

Indicates the vertical axis component of the estimated rotor flux linkage in the stationary coordinate system,

e _iβ represents the error component of the vertical axis in the stationary coordinate system between the estimated stator current and the actual stator current,

Express the horizontal axis component of the estimated rotor flux linkage in the stationary coordinate system,

k ₂ represents the rotor flux linkage error gain,

e _λα represents the error component of the horizontal axis in the stationary coordinate system between the estimated rotor flux linkage and the actual rotor flux linkage,

Indicates the vertical axis component of the estimated rotor flux linkage in the stationary coordinate system,

e _λβ represents the error component of the vertical axis in the stationary coordinate system between the estimated rotor flux linkage and the actual rotor flux linkage,

Indicates the horizontal axis component of the estimated rotor flux linkage in the stationary coordinate system,

k _p represents the proportional gain of the proportional-integral controller,

k _i represents the integral gain of the proportional-integral controller,

i _sq represents the vertical axis component of the actual stator current in the rotating coordinate system,

Indicates the vertical axis component of the estimated rotor current in the rotating coordinate system,

Indicates the horizontal axis component of the estimated rotor flux linkage in the rotating coordinate system,

k represents the rotor flux amplitude error coefficient,

i _sd represents the horizontal axis component of the actual stator current in the rotating coordinate system,

Indicates the horizontal axis component of the estimated stator current in the rotating coordinate system,

i _λ is the rotor flux phase error coefficient,

Step 3. Replace the error feedback matrix G of the observer obtained in step 1 with the error feedback matrix in the existing full-order flux observer, and replace the transformed rotational speed adaptive law equation obtained in step 2 with

${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(i_{\mathrm{sq}}-{\hat{i}}_{\mathrm{sq}}){\widehat{\mathrm{\λ}}}_{\mathrm{rd}}+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}]$ (Formula 3)

To replace the speed adaptive law in the existing full-order flux observer, that is, to successfully obtain a full-order flux observer based on the observed flux error of the asynchronous motor without a speed sensor.

In the second step, according to the known rotational speed adaptive law equation:

${\widehat{\mathrm{\ω}}}_r=k_1(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})-k_2(e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})$ (Formula 2),

Obtain the adaptive law equation of the rotational speed after deformation

${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(i_{\mathrm{sq}}-{\hat{i}}_{\mathrm{sq}}){\widehat{\mathrm{\λ}}}_{\mathrm{rd}}+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}]$ (Formula 3)

The specific process is,

(Equation 2),

$e_{\mathrm{i\α}}=i_{\mathrm{s\α}}-{\hat{i}}_{\mathrm{s\α}}$ (Equation 4),

$e_{\mathrm{i\β}}=i_{\mathrm{s\β}}-{\hat{i}}_{\mathrm{s\β}}$ (Equation 5),

$e_{\mathrm{\λ\α}}={\mathrm{\λ}}_{\mathrm{r\α}}-{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}$ (Equation 6),

$e_{\mathrm{\λ\β}}={\mathrm{\λ}}_{\mathrm{r\β}}-{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}$ (Equation 7),

Among them, i _sα represents the actual value of the stator current component on the horizontal axis in the static coordinates,

represents the estimated value of the stator current component on the transverse axis in stationary coordinates,

i _sβ represents the actual value of the stator current component on the vertical axis under the static coordinates, represents the estimated value of the stator current component on the longitudinal axis in stationary coordinates,

λ _rα represents the actual value of the flux linkage component of the horizontal axis rotor in the static coordinates, Indicates the estimated value of the flux linkage component of the horizontal axis rotor in stationary coordinates,

λ _rβ represents the actual value of the flux linkage component of the longitudinal axis rotor in the static coordinates,

Indicates the estimated value of the rotor flux component on the longitudinal axis in stationary coordinates,

Substituting (Equation 4) to (Equation 7) into (Equation 2) of , after simplification, we get: $e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}={\mathrm{\λ}}_{\mathrm{r\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-{\mathrm{\λ}}_{\mathrm{r\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=\sqrt{{\mathrm{\λ}}_{\mathrm{r\α}}^2+{\mathrm{\λ}}_{\mathrm{r\β}}^2}\&Center\; Dot;\sqrt{{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}^2+{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}^2}\left(\frac{{\mathrm{\λ}}_{\mathrm{r\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-{\mathrm{\λ}}_{\mathrm{r\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}}{\sqrt{{\mathrm{\λ}}_{\mathrm{r\α}}^2+{\mathrm{\λ}}_{\mathrm{r\β}}^2}\&Center\; Dot;\sqrt{{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}^2+{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}^2}}\right)$ (Equation 8),

Assuming that in the stationary coordinate system, the actual rotor flux vector and the estimated rotor flux vector The included angles with the α coordinate axis are θ and and θ and The difference is △θ, therefore, according to the rotation speed of the rotor flux vector is equal to the rotation speed of the stator current vector, (Formula 8) can be obtained after deformation:

$e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=\left|{\stackrel{\&Right\; Arrow;}{\mathrm{\λ}}}_r\right|\&Center\; Dot;\left|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\right|(\sin \widehat{\mathrm{\θ}}\cos \mathrm{\θ}-\cos \widehat{\mathrm{\θ}}\sin \mathrm{\θ})=-\sin \mathrm{\Δ\θ}({\left|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\right|}^2+\mathrm{\Δ\λ}|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\left|\right)$ (Formula 9)

in, is the estimated rotor flux amplitude, is the actual rotor flux amplitude, △λ is the magnitude error between the actual rotor flux and the estimated rotor flux, and △λ is 0,

make

$k={\left|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\right|}^2+\mathrm{\Δ\λ}\left|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\right|$ (Equation 10),

Among them, k is the rotor flux amplitude error coefficient,

In an asynchronous motor, the spatial rotation speeds of the rotor flux vector, the stator flux vector and the stator current vector are consistent, and in the observer, the spatial rotation speeds of the three are also consistent. Therefore, the actual rotor flux rotation The error between the angle and the estimated rotor flux rotation angle is equal to the error between the actual stator current vector rotation angle and the observed stator current rotation angle, which is obtained by using the cosine law,

$\sin \mathrm{\Δ\θ}=\frac{|i_{\mathrm{sq}}{\hat{i}}_{\mathrm{sd}}-i_{\mathrm{sd}}{\hat{i}}_{\mathrm{sq}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\&Center\; Dot;\left|{\stackrel{\widehat{\&Right\; Arrow;}}{i}}_{\mathrm{the\; s}}\right|}$ (Equation 11),

in, represents the actual stator current vector, represents the estimated stator current vector magnitude,

Substituting (Equation 10) and (Equation 11) into (Equation 9) yields

$e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=-k\frac{|i_{\mathrm{sq}}{\hat{i}}_{\mathrm{sd}}-i_{\mathrm{sd}}{\hat{i}}_{\mathrm{sq}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\&Center\; Dot;\left|{\stackrel{\widehat{\&Right\; Arrow;}}{i}}_{\mathrm{the\; s}}\right|}$ (Equation 12),

Will Substituting into (Equation 12),

$e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=-k\frac{\left|i_{\mathrm{sq}}\right||i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\·\left|{\stackrel{\widehat{\&Right\; Arrow;}}{i}}_{\mathrm{the\; s}}\right|}$ (Equation 13),

Use the PI regulator (k _p +k _i ∫dt) to replace k ₁ and k ₂ in (Formula 2), and substitute (Formula 13) into (Formula 2), that is, ${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}].$

Described existing full-order flux observer comprises A, B, C, G, 1/s, speed adaptive rate, angle calculation module, an adder and two subtractors, and described A represents full-order Flux linkage observation matrix, B represents the voltage input matrix, C represents the current output matrix, 1/s represents the integral operation,

The adder is used to sum the output voltage signal of B, the observation signal of A output and the error compensation signal of G output to obtain the rotor flux linkage differential signal,

1/s is used to perform an integral operation on the differential signal of the rotor flux linkage output by the adder to obtain the rotor flux linkage signal, and send the rotor flux linkage signal to C, Α, the angle calculation module, and the speed adaptive rate, respectively.

C is used to output the horizontal axis component of the estimated stator current in the rotating coordinate system and estimate the vertical axis component of the stator current in the rotating coordinate system

Among them, a subtractor is used to compare the horizontal axis component i _sd of the input actual stator current rotating coordinate system and the horizontal axis component of the estimated stator current rotating coordinate system As a difference, the error signal of the horizontal axis component of the stator current in the rotating coordinate system is obtained, and the error signal of the horizontal axis component of the stator current in the rotating coordinate system is sent to the speed adaptive rate and G,

Another subtractor is used to compare the vertical axis component i _sq of the input actual stator current rotating coordinate system and the vertical axis component of the estimated stator current rotating coordinate system As a difference, the error signal of the stator current in the vertical axis component of the rotating coordinate system is obtained, and the error signal of the stator current in the rotating coordinate system of the vertical axis component is sent to the speed adaptive rate and G at the same time,

The angle calculation module is used to calculate the angle of the rotor flux signal, A is used to output the observation signal, and the speed adaptation rate is used to output the speed feedback signal, and the speed feedback signal is sent to A.

The full-order flux observer of the asynchronous motor without speed sensor based on the observation of flux linkage error obtained by the present invention is specifically applied in the general-purpose frequency converter speed sensorless vector control system, and the logic mechanism schematic diagram of the general-purpose frequency converter speed sensorless vector control system See Figure 3 for details.

The method of the present invention is based on the orientation of the rotor flux linkage in the two-phase rotating coordinate system. The rotating dq coordinate system is consistent with the rotation speed of the rotor flux vector, so that the d-axis coincides with the rotor flux vector, and the rotor flux vector is calculated. The rotation angle of the chain vector, which is used to transform the stator current three-phase stationary coordinate system and the two-phase rotating coordinate system, the transformation formula is as follows:

$\left[\begin{array}{c}{i}_{\mathrm{s\α}}\\ i_{\mathrm{s\β}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{i}_u\\ i_V\\ i_W\end{array}\right]$ and $\left[\begin{array}{c}{i}_{\mathrm{sd}}\\ i_{\mathrm{sq}}\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{\θ}& -\sin \mathrm{\θ}\\ \sin \mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{c}{i}_{\mathrm{s\α}}\\ i_{\mathrm{s\β}}\end{array}\right]$

Among them, θ is the rotation angle of the rotor magnetic field calculated by using the estimated rotor flux linkage, and its calculation formula is:

Among them, i _sα represents the horizontal axis component of the actual stator current static coordinate system, is _β represents the vertical axis component of the actual stator current static coordinate system, i _U represents the first phase of the three-phase stator current, and i _V represents the second phase of the three-phase stator current phase, i _W represents the third phase of the three-phase stator current,

Finally, the current inner loop of the vector control system is formed by using the current command and the sampled and decomposed dq axis current, and the command voltage is output. After SVPWM modulation, a switching signal is generated to control the opening and closing of the switching tube, and finally achieve the purpose of frequency conversion speed regulation.

The induction motor is driven and controlled by a general frequency converter speed sensorless vector control system. The parameters of the induction motor are as follows: rated voltage: 380V, rated current 15.4A, rated power 7.5Kw, rated speed 1440r/min, rated frequency 50Hz , the speed detection encoder line number is 5000P/R, after 1028 subdivisions, the total number is 5×10 ⁶ ;

Figure 4 is the waveform diagram of the rotor speed under vector control with a speed sensor. The number of lines of the speed sensor used in Figure 4 is 1000P/R. The application of sensor detection equipment, so even when there is speed sensor control, the rotation speed still has 3rpm fluctuations, so it can be concluded that the low-speed performance of the motor without speed sensor vector control is similar to the low-speed performance of the motor with speed sensor vector control, This shows the effectiveness of the method proposed by the present invention. Fig. 5 is the rotational speed waveform diagram during the speed sensorless vector control. Compared with the speed sensor vector control in Fig. 4 and the speed sensorless vector control in Fig. 5, the rotational speed fluctuation does not change greatly.

Fig. 6 is under the speed sensorless vector control condition, when the load fluctuation is 34% of the rated torque, the rotor speed waveform diagram, using when the load fluctuation is 34% of the rated torque, based on the observed flux linkage obtained by the present invention The error-free asynchronous motor has a full-order flux observer without a speed sensor, and the anti-disturbance experiment is carried out. The system can still maintain stability at a very low speed. See Figures 7 to 10 for details. The rpm speed command is 100% of the rated load, and the load fluctuation is 6%. When there is a speed sensor vector control in Figure 8, the 1.5rpm speed command is 100% of the rated load, and the load fluctuation is 6%. In Figure 9, there is no speed sensor vector control, 1.5rpm The speed command is 100% of the rated load, and the load fluctuation is 6%. In Figure 10, the speed sensorless vector control, the 1.5rpm speed command is 100% of the rated load, and the load fluctuation is 6%. Compared with the speed sensor vector control and the speed sensor vector control , the effect is similar when the motor is running at a very low speed, and it can keep the system running stably without bad changes.

In order to ensure the observation accuracy and system stability of the observer at the same time, the present invention designs the error feedback matrix coefficients of the full-order flux observer according to the following criteria: (1) The real part of the pole of the observer is smaller than the real part of the pole of the asynchronous motor, and both are Negative numbers, so that it can ensure that the convergence speed of the observed flux linkage is greater than that of the real flux linkage; (2) The real parts of the zero and pole points of the transfer function of the estimated rotational speed are all negative numbers, ensuring that the estimated rotational speed can converge under any system gain; ( 3) Use the error between the estimated flux linkage and the real flux linkage to ensure that the system is equivalent to a current model when the motor is running at low speed, and the system is equivalent to a voltage model when the motor is running at high speed, so as to reduce the magnitude error and phase of the observed flux linkage error; and according to the phase angle error between the estimated flux linkage and the actual flux linkage, the rotor flux linkage phase error coefficient i _λ in the rotational speed adaptive law is designed, and the rotor flux linkage amplitude error coefficient k is introduced to increase the accuracy of the estimated rotational speed.

The beneficial effect brought by the present invention is that since the problem of the accuracy and stability of the system flux linkage estimation is solved by using the rotational speed adaptive law and the full-order flux linkage error feedback matrix respectively, it can ensure that the motor can operate under the condition of no speed sensor. Stable operation for a long time at very low speed (1.5rpm). And because fewer parameters are introduced, the present invention has stronger versatility. When the motor runs at a very low speed, the accuracy of the sensorless full-order flux observer of the asynchronous motor based on the observed flux error of the present invention is increased by more than 30%, so that the speed regulating system can run stably.

Description of drawings

Fig. 1 is a schematic diagram of the logical structure of the existing full-order flux linkage observer described in the third embodiment;

Fig. 2 is a schematic diagram of the logic structure of the adaptive law equation of the rotational speed after deformation in the first embodiment; wherein, PI is a proportional-integral controller, " "Denotes a subtractor," "Denotes an adder,

Fig. 3 is a schematic diagram of the logical structure of the general frequency converter speed sensorless vector control system in the content of the invention; wherein, is the speed command signal, is the flux linkage instruction signal, is the lower horizontal axis component of the stator current command static coordinate system, is the vertical axis component of the stator current command in the stationary coordinate system, is the stator voltage vector, Indicates stator voltage vector command, SVPWM is space vector pulse width modulation, dq\αβ indicates rotating coordinate transformation, αβ\abc indicates stationary coordinate transformation;

Fig. 4 is the waveform diagram of the rotor speed when there is speed sensor vector control;

Fig. 5 is the waveform diagram of the rotor speed during the speed sensorless vector control;

Figure 6 is a waveform diagram of the rotor speed when the load fluctuation is 34% of the rated torque under the condition of speed sensorless vector control;

Figure 7 is a waveform diagram of the rotor speed when the induction motor runs at 1.5rpm when there is a speed sensor vector control;

Figure 8 is a waveform diagram of the stator current, torque current and flux linkage current when the induction motor runs at 1.5rpm when there is a speed sensor vector control;

Figure 9 is a waveform diagram of the rotor speed when the induction motor runs at 1.5rpm during the speed sensorless vector control;

Figure 10 is the waveform diagram of stator current, torque current and flux linkage current when the induction motor is running at 1.5rpm under speed sensorless vector control.

detailed description

Specific Embodiment 1: Refer to Fig. 2 to illustrate this embodiment. The acquisition method of a full-order flux observer for an asynchronous motor without a speed sensor based on the observation of flux linkage error described in this embodiment is based on the existing full-order Flux linkage observer, the method includes the following steps,

Step 1. When the following three conditions are met, obtain 4 error feedback coefficients, and the 4 error feedback coefficients are g ₁ , g ₂ , g ₃ and g ₄ respectively, and substitute the obtained 4 error feedback coefficients into

$G={\left[\begin{array}{cccc}{g}_1& {-g}_2& g_3& {-g}_4\\ g_2& g_1& g_4& g_3\end{array}\right]}^T$ (Formula 1)

In, get G,

Among them, G represents the error feedback matrix of the observer,

The three conditions are,

Condition 1: The real part of the pole of the observer is smaller than the real part of the pole of the asynchronous motor, and both are negative numbers,

Condition 2: The real parts of the poles and zeros of the estimated speed transfer function are all negative numbers,

Condition 3: Use the error between the estimated flux linkage and the real flux linkage to ensure that the system is equivalent to a current model when the motor is running at low speed, and the system is equivalent to a voltage model when the motor is running at high speed;

Step 2. According to the known rotational speed adaptive law equation:

${\widehat{\mathrm{\ω}}}_r=k_1(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})-k_2(e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})$ (Formula 2),

Obtain the adaptive law equation of the rotational speed after deformation

${\widehat{\mathrm{\ω}}}_r=k_1(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})-k_2(e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})$ (Formula 3),

in, represents the estimated motor speed,

k ₁ represents the stator current error gain,

e _iα represents the error component of the horizontal axis in the stationary coordinate system between the estimated stator current and the actual stator current,

Indicates the vertical axis component of the estimated rotor flux linkage in the stationary coordinate system,

e _iβ represents the error component of the vertical axis in the stationary coordinate system between the estimated stator current and the actual stator current,

Express the horizontal axis component of the estimated rotor flux linkage in the stationary coordinate system,

k ₂ represents the rotor flux linkage error gain,

e _λα represents the error component of the horizontal axis in the stationary coordinate system between the estimated rotor flux linkage and the actual rotor flux linkage,

Indicates the vertical axis component of the estimated rotor flux linkage in the stationary coordinate system,

e _λβ represents the error component of the vertical axis in the stationary coordinate system between the estimated rotor flux linkage and the actual rotor flux linkage,

Indicates the horizontal axis component of the estimated rotor flux linkage in the stationary coordinate system,

k _p represents the proportional gain of the proportional-integral controller,

k _i represents the integral gain of the proportional-integral controller,

i _sq represents the vertical axis component of the actual stator current in the rotating coordinate system,

Indicates the vertical axis component of the estimated rotor current in the rotating coordinate system,

Indicates the horizontal axis component of the estimated rotor flux linkage in the rotating coordinate system,

k represents the rotor flux amplitude error coefficient,

i _sd represents the horizontal axis component of the actual stator current in the rotating coordinate system,

Indicates the horizontal axis component of the estimated stator current in the rotating coordinate system,

i _λ is the rotor flux phase error coefficient,

Step 3. Replace the error feedback matrix G of the observer obtained in step 1 with the error feedback matrix in the existing full-order flux observer, and replace the transformed rotational speed adaptive law equation obtained in step 2 with

${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(i_{\mathrm{sq}}-{\hat{i}}_{\mathrm{sq}}){\widehat{\mathrm{\λ}}}_{\mathrm{rd}}+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}]$ (Formula 3)

To replace the speed adaptive law in the existing full-order flux observer, that is, to successfully obtain a full-order flux observer based on the observed flux error of the asynchronous motor without a speed sensor.

Specific embodiment 2: Referring to Fig. 1 to illustrate this embodiment, the difference between this embodiment and the acquisition method of a full-order flux observer without a speed sensor for an asynchronous motor based on the observation of flux linkage error described in Embodiment 1 is that the In the second step mentioned above, according to the known rotational speed adaptive law equation:

${\widehat{\mathrm{\ω}}}_r=k_1(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})-k_2(e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})$ (Formula 2),

Obtain the adaptive law equation of the rotational speed after deformation

${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(i_{\mathrm{sq}}-{\hat{i}}_{\mathrm{sq}}){\widehat{\mathrm{\λ}}}_{\mathrm{rd}}+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}]$ (Formula 3)

The specific process is,

(Equation 2),

$e_{\mathrm{i\α}}=i_{\mathrm{s\α}}-{\hat{i}}_{\mathrm{s\α}}$ (Equation 4),

$e_{\mathrm{i\β}}=i_{\mathrm{s\β}}-{\hat{i}}_{\mathrm{s\β}}$ (Equation 5),

$e_{\mathrm{\λ\α}}={\mathrm{\λ}}_{\mathrm{r\α}}-{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}$ (Equation 6),

$e_{\mathrm{\λ\β}}={\mathrm{\λ}}_{\mathrm{r\β}}-{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}$ (Equation 7),

Among them, i _sα represents the actual value of the stator current component on the horizontal axis in the static coordinates,

represents the estimated value of the stator current component on the transverse axis in stationary coordinates,

i _sβ represents the actual value of the stator current component on the vertical axis under the static coordinates, represents the estimated value of the stator current component on the longitudinal axis in stationary coordinates,

λ _rα represents the actual value of the flux linkage component of the horizontal axis rotor in the static coordinates, Indicates the estimated value of the flux linkage component of the horizontal axis rotor in stationary coordinates,

λ _rβ represents the actual value of the flux linkage component of the longitudinal axis rotor in the static coordinates,

Indicates the estimated value of the rotor flux component on the longitudinal axis in stationary coordinates,

Substituting (Equation 4) to (Equation 7) into (Equation 2) of , after simplification, we get: $e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}={\mathrm{\λ}}_{\mathrm{r\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-{\mathrm{\λ}}_{\mathrm{r\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=\sqrt{{\mathrm{\λ}}_{\mathrm{r\α}}^2+{\mathrm{\λ}}_{\mathrm{r\β}}^2}\·\sqrt{{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}^2+{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}^2}\left(\frac{{\mathrm{\λ}}_{\mathrm{r\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-{\mathrm{\λ}}_{\mathrm{r\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}}{\sqrt{{\mathrm{\λ}}_{\mathrm{r\α}}^2+{\mathrm{\λ}}_{\mathrm{r\β}}^2}\·\sqrt{{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}^2+{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}^2}}\right)$ (Equation 8),

Assuming that in the stationary coordinate system, the actual rotor flux vector and the estimated rotor flux vector The included angles with the α coordinate axis are θ and and θ and The difference is △θ, therefore, according to the rotation speed of the rotor flux vector is equal to the rotation speed of the stator current vector, (Formula 8) can be obtained after deformation: $e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=\left|{\stackrel{\&Right\; Arrow;}{\mathrm{\λ}}}_r\right|\&Center\; Dot;\left|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\right|(\sin \widehat{\mathrm{\θ}}\cos \mathrm{\θ}-\cos \widehat{\mathrm{\θ}}\sin \mathrm{\θ})=-\sin \mathrm{\Δ\θ}({\left|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\right|}^2+\mathrm{\Δ\λ}|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\left|\right)$ (Formula 9)

in, is the estimated rotor flux amplitude, is the actual rotor flux amplitude, △λ is the magnitude error between the actual rotor flux and the estimated rotor flux, and △λ is 0,

make

$k={\left|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\right|}^2+\mathrm{\Δ\λ}\left|{\stackrel{\widehat{\&Right\; Arrow;}}{\mathrm{\λ}}}_r\right|$ (Equation 10),

Among them, k is the rotor flux amplitude error coefficient,

In an asynchronous motor, the spatial rotation speeds of the rotor flux vector, the stator flux vector and the stator current vector are consistent, and in the observer, the spatial rotation speeds of the three are also consistent. Therefore, the actual rotor flux rotation The error between the angle and the estimated rotor flux rotation angle is equal to the error between the actual stator current vector rotation angle and the observed stator current rotation angle, which is obtained by using the cosine law,

$\sin \mathrm{\Δ\θ}=\frac{|i_{\mathrm{sq}}{\hat{i}}_{\mathrm{sd}}-i_{\mathrm{sd}}{\hat{i}}_{\mathrm{sq}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\&Center\; Dot;\left|{\stackrel{\widehat{\&Right\; Arrow;}}{i}}_{\mathrm{the\; s}}\right|}$ (Equation 11),

in, represents the actual stator current vector, represents the estimated stator current vector magnitude,

Substituting (Equation 10) and (Equation 11) into (Equation 9) yields

$e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=-k\frac{|i_{\mathrm{sq}}{\hat{i}}_{\mathrm{sd}}-i_{\mathrm{sd}}{\hat{i}}_{\mathrm{sq}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\&Center\; Dot;\left|{\stackrel{\widehat{\&Right\; Arrow;}}{i}}_{\mathrm{the\; s}}\right|}$ (Equation 12),

Will Substituting into (Equation 12),

$e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=-k\frac{\left|i_{\mathrm{sq}}\right||i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\&Center\; Dot;\left|{\stackrel{\widehat{\&Right\; Arrow;}}{i}}_{\mathrm{the\; s}}\right|}$ (Equation 13),

Use the PI regulator (k _p +k _i ∫dt) to replace k ₁ and k ₂ in (Formula 2), and substitute (Formula 13) into (Formula 2), that is, ${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}].$

Specific embodiment three: Referring to FIG. 3 to illustrate this embodiment, the difference between this embodiment and the acquisition method of a full-order flux observer without a speed sensor for an asynchronous motor based on observing flux linkage errors described in the first embodiment is that the The existing full-order flux observer described includes A, B, C, G, 1/s, speed adaptation rate, angle calculation module, an adder and two subtractors, and the described A represents the full-order flux Chain observation matrix, B represents the voltage input matrix, C represents the current output matrix, 1/s represents the integral operation,

The adder is used to sum the output voltage signal of B, the observation signal of A output and the error compensation signal of G output to obtain the rotor flux linkage differential signal,

1/s is used to perform an integral operation on the differential signal of the rotor flux linkage output by the adder to obtain the rotor flux linkage signal, and send the rotor flux linkage signal to C, Α, the angle calculation module, and the speed adaptive rate, respectively.

C is used to output the horizontal axis component of the estimated stator current in the rotating coordinate system and estimate the vertical axis component of the stator current in the rotating coordinate system

Among them, a subtractor is used to compare the horizontal axis component i _sd of the input actual stator current rotating coordinate system and the horizontal axis component of the estimated stator current rotating coordinate system As a difference, the error signal of the horizontal axis component of the stator current in the rotating coordinate system is obtained, and the error signal of the horizontal axis component of the stator current in the rotating coordinate system is sent to the speed adaptive rate and G,

Another subtractor is used to compare the vertical axis component i _sq of the input actual stator current rotating coordinate system and the vertical axis component of the estimated stator current rotating coordinate system As a difference, the error signal of the stator current in the vertical axis component of the rotating coordinate system is obtained, and the error signal of the stator current in the rotating coordinate system of the vertical axis component is sent to the speed adaptive rate and G at the same time,

The angle calculation module is used to calculate the angle of the rotor flux signal, A is used to output the observation signal, and the speed adaptation rate is used to output the speed feedback signal, and the speed feedback signal is sent to A.

Claims (3)

1. The acquisition method of the full-order flux observer based on the asynchronous motor speed sensor without observing flux linkage error, the method is realized based on the existing full-order flux observer, it is characterized in that the method comprises the following steps, Step 1. When the following three conditions are met, obtain 4 error feedback coefficients, and the 4 error feedback coefficients are g ₁ , g ₂ , g ₃ and g ₄ respectively, and substitute the obtained 4 error feedback coefficients into $G={\left[\begin{array}{cccc}{g}_1& {-g}_2& g_3& {-g}_4\\ g_2& g_1& g_4& g_3\end{array}\right]}^T$ (Formula 1) In, get G, Among them, G represents the error feedback matrix of the observer, The three conditions are, Condition 1: The real part of the pole of the observer is smaller than the real part of the pole of the asynchronous motor, and both are negative numbers, Condition 2: The real parts of the poles and zeros of the estimated speed transfer function are all negative numbers, Condition 3: Use the error between the estimated flux linkage and the real flux linkage to ensure that the system is equivalent to a current model when the motor is running at low speed, and the system is equivalent to a voltage model when the motor is running at high speed; Step 2. According to the known rotational speed adaptive law equation: ${\widehat{\mathrm{\ω}}}_r=k_1(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})-k_2(e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})$ (Formula 2), Obtain the adaptive law equation of the rotational speed after deformation ${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(i_{\mathrm{sq}}-{\hat{i}}_{\mathrm{sq}}){\widehat{\mathrm{\λ}}}_{\mathrm{rd}}+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}]$ (Formula 3), in, represents the estimated motor speed, k ₁ represents the stator current error gain, e _iα represents the error component of the horizontal axis in the stationary coordinate system between the estimated stator current and the actual stator current, Indicates the vertical axis component of the estimated rotor flux linkage in the stationary coordinate system, e _iβ represents the error component of the vertical axis in the stationary coordinate system between the estimated stator current and the actual stator current, Express the horizontal axis component of the estimated rotor flux linkage in the stationary coordinate system, k ₂ represents the rotor flux linkage error gain, e _λα represents the error component of the horizontal axis in the stationary coordinate system between the estimated rotor flux linkage and the actual rotor flux linkage, Indicates the vertical axis component of the estimated rotor flux linkage in the stationary coordinate system, e _λβ represents the error component of the vertical axis in the stationary coordinate system between the estimated rotor flux linkage and the actual rotor flux linkage, Indicates the horizontal axis component of the estimated rotor flux linkage in the stationary coordinate system, k _p represents the proportional gain of the proportional-integral controller, k _i represents the integral gain of the proportional-integral controller, i _sq represents the vertical axis component of the actual stator current in the rotating coordinate system, Indicates the vertical axis component of the estimated rotor current in the rotating coordinate system, Indicates the horizontal axis component of the estimated rotor flux linkage in the rotating coordinate system, k represents the rotor flux amplitude error coefficient, i _sd represents the horizontal axis component of the actual stator current in the rotating coordinate system, Indicates the horizontal axis component of the estimated stator current in the rotating coordinate system, i _λ is the rotor flux phase error coefficient, Step 3. Replace the error feedback matrix G of the observer obtained in step 1 with the error feedback matrix in the existing full-order flux observer, and replace the transformed rotational speed adaptive law equation obtained in step 2 with ${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(i_{\mathrm{sq}}-{\hat{i}}_{\mathrm{sq}}){\widehat{\mathrm{\λ}}}_{\mathrm{rd}}+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}]$ (Formula 3) To replace the speed adaptive law in the existing full-order flux observer, that is, to successfully obtain a full-order flux observer based on the observed flux error of the asynchronous motor without a speed sensor. 2. the acquisition method based on the full-order flux observer of the asynchronous motor without speed sensor according to claim 1, it is characterized in that, in the described step 2, according to the known rotational speed adaptive law equation : ${\widehat{\mathrm{\ω}}}_r=k_1(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})-k_2(e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})$ (Formula 2), Obtain the adaptive law equation of the rotational speed after deformation ${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\mathrm{\λdt})[(i_{\mathrm{sq}}-{\hat{i}}_{\mathrm{sq}}){\widehat{\mathrm{\λ}}}_{\mathrm{rd}}+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}]$ (Formula 3) The specific process is, (Formula 2), $e_{\mathrm{i\α}}=i_{\mathrm{s\α}}-{\hat{i}}_{\mathrm{s\α}}$ (Formula 4), $e_{\mathrm{i\β}}=i_{\mathrm{s\β}}-{\hat{i}}_{\mathrm{s\β}}$ (Formula 5), $e_{\mathrm{\λ\α}}={\mathrm{\λ}}_{\mathrm{r\α}}-{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}$ (Formula 6), $e_{\mathrm{\λ\β}}={\mathrm{\λ}}_{\mathrm{r\β}}-{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}$ (Formula 7), Among them, i _sα represents the actual value of the stator current component on the horizontal axis in the static coordinates, represents the estimated value of the stator current component on the transverse axis in stationary coordinates, i _sβ represents the actual value of the stator current component on the vertical axis under the static coordinates, represents the estimated value of the stator current component on the longitudinal axis in stationary coordinates, λ _rα represents the actual value of the flux linkage component of the horizontal axis rotor in the static coordinates, Indicates the estimated value of the flux linkage component of the horizontal axis rotor in stationary coordinates, λ _rβ represents the actual value of the flux linkage component of the longitudinal axis rotor in the static coordinates, Indicates the estimated value of the rotor flux component on the longitudinal axis in stationary coordinates, Substituting (Equation 4) to (Equation 7) into (Equation 2) , after simplification, we get: $e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}={\mathrm{\λ}}_{\mathrm{r\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-{\mathrm{\λ}}_{\mathrm{r\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=\sqrt{{\mathrm{\λ}}_{\mathrm{r\α}}^2+{\mathrm{\λ}}_{\mathrm{r\β}}^2}\&Center\; Dot;\sqrt{{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}^2+{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}^2}\left(\frac{{\mathrm{\λ}}_{\mathrm{r\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-{\mathrm{\λ}}_{\mathrm{r\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}}{\sqrt{{\mathrm{\λ}}_{\mathrm{r\α}}^2+{\mathrm{\λ}}_{\mathrm{\β}}^2}\&Center\; Dot;\sqrt{{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}^2+{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}^2}}\right)$ (Formula 8), Assuming that in the stationary coordinate system, the actual rotor flux vector and the estimated rotor flux vector The included angles with the α coordinate axis are θ and and θ and The difference is △θ, therefore, according to the rotation speed of the rotor flux vector is equal to the rotation speed of the stator current vector, (Formula 8) can be obtained after deformation: $e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=\left|{\stackrel{\&Right\; Arrow;}{\mathrm{\λ}}}_r\right|\·\left|{\widehat{\stackrel{\&Right\; Arrow;}{\mathrm{\λ}}}}_r\right|(\sin \widehat{\mathrm{\θ}}\cos \mathrm{\θ}-\cos \widehat{\mathrm{\θ}}\sin \mathrm{\θ})=-\sin \mathrm{\Δ\θ}({\left|{\widehat{\stackrel{\&Right\; Arrow;}{\mathrm{\λ}}}}_r\right|}^2+\mathrm{\Δ\λ}{|\widehat{\stackrel{\&Right\; Arrow;}{\mathrm{\λ}}}}_r|)$ (Formula 9) in, is the estimated rotor flux amplitude, is the actual rotor flux amplitude, △λ is the magnitude error between the actual rotor flux and the estimated rotor flux, and △λ is 0, make $k={\left|{\widehat{\stackrel{\&Right\; Arrow;}{\mathrm{\λ}}}}_r\right|}^2+\mathrm{\Δ\λ}\left|{\widehat{\stackrel{\&Right\; Arrow;}{\mathrm{\λ}}}}_r\right|$ (Formula 10), Among them, k is the rotor flux amplitude error coefficient, Let the error between the actual rotor flux rotation angle and the estimated rotor flux rotation angle be equal to the error between the actual stator current vector rotation angle and the observed stator current rotation angle, and use the cosine law to obtain, $\sin \mathrm{\Δ\θ}=\frac{|i_{\mathrm{sq}}{\hat{i}}_{\mathrm{sd}}-i_{\mathrm{sd}}{\hat{i}}_{\mathrm{sq}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\·\left|{\widehat{\stackrel{\&Right\; Arrow;}{i}}}_{\mathrm{the\; s}}\right|}$ (Formula 11), in, represents the actual stator current vector, represents the estimated stator current vector magnitude, Substituting (Formula 10) and (Formula 11) into (Formula 9), we get $e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=-k\frac{|i_{\mathrm{sq}}{\hat{i}}_{\mathrm{sd}}-i_{\mathrm{sd}}{\hat{i}}_{\mathrm{sq}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\·\left|{\widehat{\stackrel{\&Right\; Arrow;}{i}}}_{\mathrm{the\; s}}\right|}$ (Formula 12), Will Substituting into (Equation 12), $e_{\mathrm{\λ\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{\λ\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}}=-k\frac{|i_{\mathrm{sq}}{\left|\right|\hat{i}}_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}}|}{\left|{\stackrel{\&Right\; Arrow;}{i}}_{\mathrm{the\; s}}\right|\&Center\; Dot;\left|{\widehat{\stackrel{\&Right\; Arrow;}{i}}}_{\mathrm{the\; s}}\right|}$ (Formula 13), Use the PI regulator (k _p +k _i ∫dt) to replace k ₁ and k ₂ in (Formula 2), and substitute (Formula 13) into (Formula 2), that is, ${\widehat{\mathrm{\ω}}}_r=(k_p+k_i\∫\mathrm{dt})[(e_{\mathrm{i\α}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\β}}-e_{\mathrm{i\β}}{\widehat{\mathrm{\λ}}}_{\mathrm{r\α}})+k(i_{\mathrm{sd}}-{\hat{i}}_{\mathrm{sd}})i_{\mathrm{\λ}}].$ 3. the acquisition method based on the full-order flux observer of the asynchronous motor speed sensor without observing flux linkage error according to claim 1, it is characterized in that, described existing full-order flux observer comprises A, B, C, G, 1/s, speed adaptive rate, angle calculation module, an adder and two subtractors, said A represents the full-order flux linkage observation matrix, B represents the voltage input matrix, and C represents the current output Matrix, 1/s means integral operation, The adder is used to sum the output voltage signal of B, the observation signal of A output and the error compensation signal of G output to obtain the rotor flux linkage differential signal, 1/s is used to perform integral operation on the differential signal of the rotor flux linkage output by the adder to obtain the rotor flux linkage signal, and send the rotor flux linkage signal to C, Α, angle calculation module, speed adaptive rate, respectively, C is used to output the horizontal axis component of the estimated stator current in the rotating coordinate system and estimate the vertical axis component of the stator current in the rotating coordinate system Among them, a subtractor is used to compare the horizontal axis component i _sd of the input actual stator current rotating coordinate system and the horizontal axis component of the estimated stator current rotating coordinate system As a difference, the error signal of the horizontal axis component of the stator current in the rotating coordinate system is obtained, and the error signal of the horizontal axis component of the stator current in the rotating coordinate system is sent to the speed adaptive rate and G, Another subtractor is used to compare the vertical axis component i _sq of the input actual stator current rotating coordinate system and the vertical axis component of the estimated stator current rotating coordinate system As a difference, the obtained stator current error signal of the vertical axis component in the rotating coordinate system is sent to the rotational speed adaptive rate and G at the same time. The angle calculation module is used to calculate the angle of the rotor flux signal, A is used to output the observation signal, and the speed adaptation rate is used to output the speed feedback signal, and the speed feedback signal is sent to A.