Method and device for detecting rotor displacement of improved filter of bearingless permanent magnet synchronous motor

Abstract

The invention provides a rotor displacement detection method and device for an improved filter of a bearingless permanent magnet synchronous motor, relates to the technical field of bearingless permanent magnet synchronous motors, and aims at solving the problem of rotor position judgment in operation of the bearingless permanent magnet synchronous motor and estimating the rotor position by adopting a back electromotive force method. The back electromotive force signal usually contains high-frequency noise, and at the moment, an improved low-pass filter is adopted for filtering so as to extract fundamental wave components related to the position of the rotor. Phase and amplitude compensation is carried out on the back electromotive force, and then filtering is carried out through a low-pass filter. And the dynamic performance, especially the low-speed performance, of the flux linkage observer can be improved. According to the method, the dynamic performance of the flux linkage observer can be effectively improved, and the reliability and accuracy of rotor displacement detection of the shaftless permanent magnet synchronous motor are improved.

Description

Technical Field

[0001] The invention relates to the technical field of bearingless permanent magnet synchronous motors, and in particular to a bearingless permanent magnet synchronous motor improved filter rotor displacement detection method and device. Background Art

[0002] Traditional aerospace vehicles have very strict weight requirements. In addition, they are required to operate stably for a long time in space. This places high demands on the lightweight, high reliability and long life of the motor. For this reason, people have proposed the concept of bearingless permanent magnet synchronous motor. However, since the motor has no bearings, it is difficult to detect the positioning of the motor rotor. Therefore, it is proposed to establish a magnetic flux model through the back-EMF method to detect the rotor position, but there is still the problem of radial suspension force winding observation error.

[0003] In view of this, this application is filed. Summary of the invention

[0004] The present invention provides a method and device for detecting rotor displacement of an improved filter of a bearingless permanent magnet synchronous motor, which can at least partially improve the above-mentioned problem.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A method for detecting rotor displacement of a bearingless permanent magnet synchronous motor with an improved filter, comprising: Obtaining preset reference values ​​of the back electromotive force of the bearingless permanent magnet synchronous motor and the radial suspension force winding flux of the bearingless permanent magnet synchronous motor, filtering and compensating the back electromotive force and the preset reference value respectively, and generating the radial suspension force winding flux; Based on the Pythagorean theorem and the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux amplitude and the magnetic flux angle; Performing compensation preprocessing on the flux amplitude and the flux angle to obtain an optimized reference value of the radial suspension force winding flux, and updating the radial suspension force winding flux based on the optimized reference value of the radial suspension force winding flux; The updated radial suspension force winding flux is subjected to coordinate transformation to obtain a final radial suspension force winding flux.

[0006] The present invention also provides a bearingless permanent magnet synchronous motor improved filter rotor displacement detection device, which comprises: An initial flux value generating unit is used to obtain a preset reference value of the back electromotive force of the bearingless permanent magnet synchronous motor and the radial suspension force winding flux of the bearingless permanent magnet synchronous motor, and to filter and compensate the back electromotive force and the preset reference value respectively to generate the radial suspension force winding flux; An amplitude angle calculation unit is used to calculate the magnetic flux of the radial suspension force winding based on the Pythagorean theorem and the tangent function to obtain the magnetic flux amplitude and the magnetic flux angle; an optimization unit, configured to pre-process the flux linkage amplitude and the flux linkage angle to obtain an optimized reference value of the radial suspension force winding flux linkage, and update the radial suspension force winding flux linkage based on the optimized reference value of the radial suspension force winding flux linkage; The coordinate conversion unit is used to perform coordinate conversion on the updated radial suspension force winding flux to obtain a final radial suspension force winding flux.

[0007] In summary, the improved filter rotor displacement detection method for bearingless permanent magnet synchronous motor aims at the problem of rotor position discrimination in the operation of bearingless permanent magnet synchronous motor, and estimates the rotor position by back electromotive force method. The back electromotive force signal usually contains high-frequency noise. At this time, an improved low-pass filter is used for filtering to extract the fundamental component related to the rotor position. The back electromotive force is first compensated for phase and amplitude, and then filtered through a low-pass filter. It helps to improve the dynamic performance of the flux observer, especially the low-speed performance. This method can effectively improve the dynamic performance of the flux observer and improve the reliability and accuracy of the rotor displacement detection of the shaftless permanent magnet synchronous motor.

[0008] Compared with the prior art, the improved filter rotor displacement detection method for the bearingless permanent magnet synchronous motor has the following characteristics: 1. The back electromotive force signal is collected through a low-pass filter to reduce the observation error of the radial suspension force winding flux, and the flux-displacement equation established thereby finally obtains the radial offset of the rotor, thereby realizing self-detection of the radial displacement of the rotor. Therefore, this method can effectively improve the accuracy of flux observation while effectively filtering high-frequency noise. 2. By using the improved low-pass filter, by exchanging the order of amplitude-phase compensation and low-pass filtering, only the signal after the frequency mutation is tracked and compensated, while the signal before the frequency mutation is maintained unchanged. The problem that the traditional low-pass filter is prone to mutation with the mutation of the input signal frequency is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic flow chart of a method for detecting rotor displacement of an improved filter for a bearingless permanent magnet synchronous motor provided by a first embodiment of the present invention; Figure 2 is a schematic diagram of a bearingless permanent magnet synchronous motor provided by a first embodiment of the present invention; Figure 3 is a schematic diagram of a model of an improved low-pass filter provided by the first embodiment of the present invention; Figure 4 It is a module schematic diagram of a bearingless permanent magnet synchronous motor improved filter rotor displacement detection device provided by the second embodiment of the present invention. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0011] refer to Figure 1 , Figure 2 As shown, the first embodiment of the present invention discloses a method for detecting rotor displacement of an improved filter of a bearingless permanent magnet synchronous motor, which can be performed by a bearingless permanent magnet synchronous motor improved filter rotor displacement detection device (hereinafter referred to as the detection device), and in particular, is performed by one or more processors in the detection device to implement the following method: S1, obtaining a preset reference value of a back electromotive force of a bearingless permanent magnet synchronous motor and a radial suspension force winding flux of the bearingless permanent magnet synchronous motor, filtering and compensating the back electromotive force and the preset reference value respectively, and generating a radial suspension force winding flux; Specifically, step S1 includes: obtaining the back electromotive force of the bearingless permanent magnet synchronous motor , ; The back EMF , The cut-off frequency is The low-pass filter is used as the input signal to obtain the back electromotive force after filtering. The expression is: ,in, is the Laplace operator; Get the preset reference value of the radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor , ; Preset reference value of radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor , Perform compensation processing to obtain the preset reference value after compensation, the expression is: ; The radial suspension force winding flux is obtained by adding the filtered back electromotive force and the compensated preset reference value. The formula is: .

[0012] See also Figure 2 , the bearingless permanent magnet synchronous motor used is Figure 2 As shown, the torque winding has 12 poles and the permanent magnet is a built-in NS radial magnetization. Therefore, in this bearingless motor, the number of permanent magnet pole pairs is 6 pairs.

[0013] In this embodiment, the improved filter rotor displacement detection method for the bearingless permanent magnet synchronous motor uses a low-pass filter to simplify the flux observation model, making the control strategy more concise and reducing the complexity of the control system. The improved low-pass filter can accurately track the flux change when the back-EMF signal frequency suddenly changes.

[0014] See also Figure 3 Specifically, obtain the stator back electromotive force signal and estimate the motor rotor position. First, add the reference value of the radial suspension force winding flux. , and obtain the back EMF , The cut-off frequency is The low-pass filter is used as the input signal, and the expression of the radial suspension force winding flux is: , where s is the Laplace operator. The two are added together to obtain the preliminary radial suspension force winding flux: , .

[0015] S2, based on the Pythagorean theorem and the tangent function, calculating the magnetic flux of the radial suspension force winding to obtain the magnetic flux amplitude and the magnetic flux angle; Specifically, step S2 includes: based on the Pythagorean theorem, calculating the flux of the initial radial suspension force winding to obtain the flux amplitude ; Based on the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux angle .

[0016] In this embodiment, the detected back electromotive force signal is compensated for phase and amplitude. Since the reference value of the added radial suspension force winding flux may have errors, further compensation is required to re-acquire a more accurate radial suspension force winding flux, that is, update the radial suspension force winding flux.

[0017] Winding flux linkage due to radial suspension force , Get the flux amplitude With Angle In a bearingless permanent magnet synchronous motor, the magnetic flux of the radial suspension winding is The two orthogonal components of the coordinate system are denoted as , , through these two components to control the radial suspension force of the rotor. And according to the Pythagorean theorem and tangent function, the magnetic flux amplitude is obtained , magnetic flux angle .

[0018] S3, performing compensation preprocessing on the flux amplitude and flux angle to obtain an optimized reference value of the radial suspension force winding flux, and updating the radial suspension force winding flux based on the optimized reference value of the radial suspension force winding flux; Specifically, step S3 includes: sequentially performing saturation limiting processing and polar coordinate / rectangular coordinate transformation processing on the flux linkage amplitude, and performing polar coordinate / rectangular coordinate transformation processing on the flux linkage angle, and converting the preset reference value of the radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor into , Optimized as the reference value of radial suspension force winding flux , ; Optimized reference value for radial suspension winding flux , Compensation is performed to obtain the optimized reference value of the supplemented radial suspension force winding flux, the formula is: ; The optimized reference value of the compensated radial suspension force winding flux is added to the back electromotive force after filtering, and the radial suspension force winding flux is updated. The updated radial suspension force winding flux formula is: .

[0019] In this embodiment, the stator flux is obtained through a low-pass filter. After saturation limiting, enter the polar / rectangular coordinate transformation and further optimize the flux linkage amplitude reference value , Specifically, for the flux amplitude Saturation limiting is performed to achieve stable suspension force, and the current is adjusted according to the difference between the reference value and the actual value to ensure that the amplitude and angle of the magnetic flux can track the predetermined reference value to achieve precise suspension force control.

[0020] S4, performing coordinate transformation on the updated radial suspension force winding flux to obtain a final radial suspension force winding flux.

[0021] Specifically, step S4 includes: performing a two-phase stationary coordinate transformation on the updated radial suspension force winding flux to obtain the final radial suspension force winding flux under the dq rotating coordinate. , .

[0022] In this embodiment, a corresponding mathematical model is established based on the relationship between the stator flux and the rotor displacement for rotor self-detection. , The radial suspension winding flux is obtained by transforming the two-phase stationary coordinates to the dq rotating coordinates. , .

[0023] Specifically, in this embodiment, the improved filter rotor displacement detection method of the bearingless permanent magnet synchronous motor can be simply described as follows: Since the radial suspension force winding flux observer is a pure integral operation, there is a dynamic tracking error problem in theory. Therefore, an improved low-pass filter is used as the input signal to replace the pure integral operation, and the order of amplitude-phase compensation and low-pass filtering is exchanged. Therefore, an improved low-pass filter model is established as follows: Figure 3 The aim is to improve the dynamic performance of flux observation without affecting the rotor radial displacement self-detection function, and to detect the rotor position more accurately and quickly. In short, the reference value of the optimized radial suspension force winding flux is , Amplitude and phase compensation and low-pass filtering are performed to obtain the radial suspension force flux observation model. This is consistent with the ideal integral operation performance and can ensure compliance with physical logic errors, avoiding the problem of traditional low-pass filters that mutate with the frequency of the input signal due to mutations, and eliminating the problem of dynamic tracking errors.

[0024] Specifically, the flux observation algorithm is as follows: The stator space flux expression is: , where Us, Is, , E are the space vectors of the motor stator voltage, current, flux linkage and induced potential under the stationary shaft system; ∠E and E are the phase angle and amplitude of the induced potential space vector respectively; is the stator electrical angular frequency, is the actual deviation. Due to the existence of parameters, measurement errors and other reasons, the ideal integrator has DC drift and saturation problems. Therefore, the corresponding stator flux expression using a low-pass filter is: ,in, is the low-pass filter cutoff frequency.

[0025] The improvement described in this method is as follows: Assume that the input signal frequency is changed from ω at time t1 1 Mutation to ω 2 , then the traditional low-pass filter output signal vector is: , the next output signal vector: ,in, and are the compensation vector function and the input vector respectively.

[0026] From the above formula, it can be seen that the amplitude and phase of the output signal change suddenly with the frequency of the input signal. Therefore, there is a dynamic tracking problem in theory. The output signal of the improved low-pass filter at time t1 is the same as that of the traditional low-pass filter. But the output vector expression at the next moment is: When the frequency of the input signal changes suddenly, since the new algorithm exchanges the order of amplitude-phase compensation and low-pass filtering, the improved low-pass filter only tracks and compensates the input signal after the frequency change according to the new frequency.

[0027] Specifically, in this embodiment, the improved filter rotor displacement detection method of the bearingless permanent magnet synchronous motor adopts an improved back electromotive force method, and uses the back electromotive force signal generated by the motor when it is running to estimate the position of the rotor. To detect the rotor displacement of the permanent magnet synchronous motor, the back electromotive force is first compensated for phase and amplitude, and then filtered through a low-pass filter. Under low-speed conditions, the improved low-pass filter can also maintain a high observation accuracy. This method can effectively improve the dynamic performance of the flux observer and improve the reliability and accuracy of the rotor displacement detection of the shaftless permanent magnet synchronous motor.

[0028] In addition, the improved filter rotor displacement detection method for the bearingless permanent magnet synchronous motor adds a low-pass filter on the basis of the back electromotive force method, which can effectively reduce the observation error of the suspension force winding flux. When running at low speed, due to the weak back electromotive force of the permanent magnet synchronous motor, the traditional observation method will cause a large error, and the use of a low-pass filter can improve the dynamic performance at low speed. The bearingless motor can also detect the rotor position at low speed. Compared with the traditional low-pass filter, the back electromotive force is low-pass filtered, and then the amplitude and phase compensation are performed on the result. The improved low-pass filter changes this order, first compensating the amplitude and phase of the back electromotive force, and then performing low-pass filtering. The self-detection of the radial displacement of the bearingless permanent magnet synchronous motor is realized, and the rotor position detection is realized through its own signal, without the existence of an external sensor.

[0029] In summary, the improved filter rotor displacement detection method for bearingless permanent magnet synchronous motor can further improve the dynamic performance of the flux observer by adopting an improved low-pass filter, thereby improving the reliability and accuracy of bearingless permanent magnet synchronous motor rotor displacement detection. While ensuring the lightweight of the permanent magnet synchronous motor, the accuracy and reliability of the motor rotor position detection are improved.

[0030] See also Figure 4 The second embodiment of the present invention provides a bearingless permanent magnet synchronous motor improved filter rotor displacement detection device, which includes: The initial flux value generating unit 201 is used to obtain the back electromotive force of the bearingless permanent magnet synchronous motor and the preset reference value of the radial suspension force winding flux of the bearingless permanent magnet synchronous motor, and respectively filter and compensate the back electromotive force and the preset reference value to generate the radial suspension force winding flux; An amplitude angle calculation unit 202 is used to calculate the magnetic flux of the radial suspension force winding based on the Pythagorean theorem and the tangent function to obtain the magnetic flux amplitude and the magnetic flux angle; The optimization unit 203 is used to perform compensation preprocessing on the flux amplitude and the flux angle to obtain an optimized reference value of the radial suspension force winding flux, and update the radial suspension force winding flux based on the optimized reference value of the radial suspension force winding flux; The coordinate conversion unit 204 is used to perform coordinate conversion on the updated radial suspension force winding flux to obtain a final radial suspension force winding flux.

[0031] Preferably, the preset reference values ​​of the back electromotive force of the bearingless permanent magnet synchronous motor and the radial suspension force winding flux of the bearingless permanent magnet synchronous motor are obtained, and the back electromotive force and the preset reference value are filtered and compensated respectively to generate the radial suspension force winding flux, specifically: Obtaining the Back EMF of a Bearingless Permanent Magnet Synchronous Motor , ; The back EMF , The cut-off frequency is The low-pass filter is used as the input signal to obtain the back electromotive force after filtering. The expression is: ,in, is the Laplace operator; Get the preset reference value of the radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor , ; Preset reference value of radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor , Perform compensation processing to obtain the preset reference value after compensation, the expression is: ; The radial suspension force winding flux is obtained by adding the filtered back electromotive force and the compensated preset reference value. The formula is: .

[0032] Preferably, based on the Pythagorean theorem and the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux amplitude and the magnetic flux angle, specifically: Based on the Pythagorean theorem, the initial radial suspension force winding flux is calculated to obtain the flux amplitude. ; Based on the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux angle .

[0033] Preferably, the flux amplitude and the flux angle are pre-processed for compensation to obtain an optimized reference value of the radial suspension force winding flux, and the radial suspension force winding flux is updated based on the optimized reference value of the radial suspension force winding flux, specifically: The flux amplitude is processed by saturation limiting, polar coordinate / rectangular coordinate transformation, and the flux angle is processed by polar coordinate / rectangular coordinate transformation, and the preset reference value of the radial suspension force winding flux of the bearingless permanent magnet synchronous motor is converted to , Optimized as the reference value of radial suspension force winding flux , ; Optimized reference value for radial suspension winding flux , Compensation is performed to obtain the optimized reference value of the supplemented radial suspension force winding flux, the formula is: ; The optimized reference value of the compensated radial suspension force winding flux is added to the back electromotive force after filtering, and the radial suspension force winding flux is updated. The updated radial suspension force winding flux formula is: .

[0034] Preferably, coordinate transformation is performed on the updated radial suspension force winding flux to obtain the final radial suspension force winding flux, specifically: The updated radial suspension force winding flux is transformed into a two-phase stationary coordinate to obtain the final radial suspension force winding flux in the dq rotating coordinate. , .

[0035] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for detecting rotor displacement of a bearingless permanent magnet synchronous motor with an improved filter, characterized in that: include: Obtaining preset reference values ​​of the back electromotive force of the bearingless permanent magnet synchronous motor and the radial suspension force winding flux of the bearingless permanent magnet synchronous motor, filtering and compensating the back electromotive force and the preset reference value respectively, and generating the radial suspension force winding flux; Based on the Pythagorean theorem and the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux amplitude and the magnetic flux angle; Performing compensation preprocessing on the flux amplitude and the flux angle to obtain an optimized reference value of the radial suspension force winding flux, and updating the radial suspension force winding flux based on the optimized reference value of the radial suspension force winding flux; Performing coordinate transformation on the updated radial suspension force winding flux to obtain a final radial suspension force winding flux; Obtain the preset reference values ​​of the back electromotive force of the bearingless permanent magnet synchronous motor and the radial suspension force winding flux of the bearingless permanent magnet synchronous motor, filter and compensate the back electromotive force and the preset reference value respectively, and generate the radial suspension force winding flux, specifically: Obtaining the Back EMF of a Bearingless Permanent Magnet Synchronous Motor , ; The back EMF , The cut-off frequency is The low-pass filter is used as the input signal to obtain the back electromotive force after filtering. The expression is: ,in, is the Laplace operator; Get the preset reference value of the radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor , ; Preset reference value of radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor , Perform compensation processing to obtain the preset reference value after compensation, the expression is: ; The radial suspension force winding flux is obtained by adding the filtered back electromotive force and the compensated preset reference value. The formula is: .

2. The improved filter rotor displacement detection method for a bearingless permanent magnet synchronous motor according to claim 1 is characterized in that: Based on the Pythagorean theorem and the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux amplitude and magnetic flux angle, which are specifically: Based on the Pythagorean theorem, the initial radial suspension force winding flux is calculated to obtain the flux amplitude. ; Based on the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux angle .

3. The improved filter rotor displacement detection method for a bearingless permanent magnet synchronous motor according to claim 2 is characterized in that: The flux amplitude and the flux angle are compensated and preprocessed to obtain an optimized reference value of the radial suspension force winding flux, and the radial suspension force winding flux is updated based on the optimized reference value of the radial suspension force winding flux, specifically: The flux amplitude is processed by saturation limiting, polar coordinate / rectangular coordinate transformation, and the flux angle is processed by polar coordinate / rectangular coordinate transformation, and the preset reference value of the radial suspension force winding flux of the bearingless permanent magnet synchronous motor is converted to , Optimized as the reference value of radial suspension force winding flux , ; Optimized reference value for radial suspension winding flux , Compensation is performed to obtain the optimized reference value of the supplemented radial suspension force winding flux, the formula is: ; The optimized reference value of the compensated radial suspension force winding flux is added to the back electromotive force after filtering, and the radial suspension force winding flux is updated. The updated radial suspension force winding flux formula is: .

4. The improved filter rotor displacement detection method for a bearingless permanent magnet synchronous motor according to claim 1 is characterized in that: The updated radial suspension force winding flux is subjected to coordinate transformation to obtain the final radial suspension force winding flux, which is specifically: Perform a two-phase stationary coordinate transformation on the updated radial suspension force winding flux to obtain the final radial suspension force winding flux under dq rotating coordinates. , .

5. A bearingless permanent magnet synchronous motor improved filter rotor displacement detection device, characterized in that: include: An initial flux value generating unit is used to obtain a preset reference value of the back electromotive force of the bearingless permanent magnet synchronous motor and the radial suspension force winding flux of the bearingless permanent magnet synchronous motor, and to filter and compensate the back electromotive force and the preset reference value respectively to generate the radial suspension force winding flux; An amplitude angle calculation unit is used to calculate the magnetic flux of the radial suspension force winding based on the Pythagorean theorem and the tangent function to obtain the magnetic flux amplitude and the magnetic flux angle; an optimization unit, configured to pre-process the flux linkage amplitude and the flux linkage angle to obtain an optimized reference value of the radial suspension force winding flux linkage, and update the radial suspension force winding flux linkage based on the optimized reference value of the radial suspension force winding flux linkage; A coordinate conversion unit, used for performing coordinate conversion on the updated radial suspension force winding flux to obtain a final radial suspension force winding flux; Obtain the preset reference values ​​of the back electromotive force of the bearingless permanent magnet synchronous motor and the radial suspension force winding flux of the bearingless permanent magnet synchronous motor, filter and compensate the back electromotive force and the preset reference value respectively, and generate the radial suspension force winding flux, specifically: Obtaining the Back EMF of a Bearingless Permanent Magnet Synchronous Motor , ; The back EMF , The cut-off frequency is The low-pass filter is used as the input signal to obtain the back electromotive force after filtering. The expression is: ,in, is the Laplace operator; Get the preset reference value of the radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor , ; Preset reference value of radial suspension force winding flux linkage of the bearingless permanent magnet synchronous motor , Perform compensation processing to obtain the preset reference value after compensation, the expression is: ; The radial suspension force winding flux is obtained by adding the filtered back electromotive force and the compensated preset reference value. The formula is: .

6. The improved filter rotor displacement detection device for a bearingless permanent magnet synchronous motor according to claim 5, characterized in that: Based on the Pythagorean theorem and the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux amplitude and magnetic flux angle, which are specifically: Based on the Pythagorean theorem, the initial radial suspension force winding flux is calculated to obtain the flux amplitude. ; Based on the tangent function, the magnetic flux of the radial suspension force winding is calculated to obtain the magnetic flux angle .

7. The improved filter rotor displacement detection device for a bearingless permanent magnet synchronous motor according to claim 6 is characterized in that: The flux amplitude and the flux angle are compensated and preprocessed to obtain an optimized reference value of the radial suspension force winding flux, and the radial suspension force winding flux is updated based on the optimized reference value of the radial suspension force winding flux, specifically: The flux amplitude is processed by saturation limiting, polar coordinate / rectangular coordinate transformation, and the flux angle is processed by polar coordinate / rectangular coordinate transformation, and the preset reference value of the radial suspension force winding flux of the bearingless permanent magnet synchronous motor is converted to , Optimized as the reference value of radial suspension force winding flux , ; Optimized reference value for radial suspension winding flux , Compensation is performed to obtain the optimized reference value of the supplemented radial suspension force winding flux, the formula is: ; The optimized reference value of the compensated radial suspension force winding flux is added to the back electromotive force after filtering, and the radial suspension force winding flux is updated. The updated radial suspension force winding flux formula is: .

8. The improved filter rotor displacement detection device for a bearingless permanent magnet synchronous motor according to claim 5, characterized in that: The updated radial suspension force winding flux is subjected to coordinate transformation to obtain the final radial suspension force winding flux, which is specifically: Perform a two-phase stationary coordinate transformation on the updated radial suspension force winding flux to obtain the final radial suspension force winding flux under dq rotating coordinates. , .

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