Permanent magnet synchronous motor static eccentric fault diagnosis method and system

Abstract

The application discloses a permanent magnet synchronous motor static eccentric fault diagnosis method and system, comprising: selecting two stator slots S1 slot and S3 slot with a circumferential angle difference of 60 degrees as an installation group on the cross section of the rotor and the stator H a1 , embedding an A group linear Hall sensor one on the center line of the S1 slot H a2 ; embedding an A group linear Hall sensor two on the center line of the S7 slot opposite to the A group linear Hall sensor one; embedding a B group linear Hall sensor on the center line of the S3 slot and the S9 slot opposite to the S3 slot; according to the signals collected by the linear Hall sensors, the permanent magnet synchronous motor is calibrated and error decoupled; when the permanent magnet synchronous motor is normally operated, an online monitoring mode is entered, the amplitude bit characteristics and the phase difference characteristics are extracted in real time, and whether the eccentric fault early warning is triggered is judged according to the amplitude bit characteristics and the phase difference characteristics. The application can realize synchronous and accurate quantification of the size and direction of the static eccentricity.

Description

Technical Field

[0001] This invention belongs to the field of motor condition monitoring and fault diagnosis technology, and particularly relates to a method and system for detecting static eccentricity faults in permanent magnet synchronous motors. Background Technology

[0002] As a critical drive component, static eccentricity faults in permanent magnet synchronous motors directly lead to increased vibration, decreased efficiency, and bearing wear, severely impacting system reliability. To effectively diagnose eccentricity faults in permanent magnet synchronous motors, existing technologies primarily employ the following methods:

[0003] Diagnostic methods based on indirect signal analysis. Patent document CN110703091A discloses a scheme for diagnosing static eccentricity by measuring the waveform distortion rate of the no-load back EMF of a multi-unit permanent magnet motor. Similarly, analysis methods based on characteristic harmonics of motor stator current or chassis vibration signals are also widely used. Due to the indirect nature of the signals, current and vibration signals are the combined result of eccentricity faults after complex electromagnetic and mechanical transmission, and are easily affected by load fluctuations, control strategies, background noise, and other concurrent faults. Diagnostic features such as specific harmonics have low signal-to-noise ratios and poor specificity, resulting in insufficient reliability. At the same time, due to weak physical correlation, it is impossible to accurately infer the magnitude and spatial orientation of the eccentricity fault offset, so only qualitative or coarse fault indications can be provided.

[0004] Diagnostic methods based on direct measurement of internal magnetic fields. To obtain more direct fault information, the air gap magnetic field is directly measured inside the motor. Linear Hall sensors, due to their small size and fast frequency response, have become the main choice for integrated monitoring. Patent document CN109541461A uses a detection coil, which is complex to install and the signal is susceptible to interference. After adopting Hall sensors, the technical problem lies in how to extract more sensitive fault features from the sensor signal. Patent document CN121025950A proposes a method of asymmetric layered installation of Hall sensors and processing harmonic signals. Patent document CN113686237A arranges three Hall sensors spatially and extracts the amplitude of the negative sequence component or specific sideband harmonics in the electrical coordinate system as fault indicators through complex signal transformations such as Clarke transform and complex factor filtering.

[0005] Despite continuous updates to the aforementioned Hall sensor-based solutions, none have effectively resolved the coupling problem between the inherent errors of the sensor itself and the actual fault signal. Inherent errors in Hall sensors, such as gain inconsistency, installation position deviation, and temperature drift, directly and unpredictably alter the amplitude of the output signal. Existing diagnostic methods rely heavily on the analysis of certain signal amplitudes, including the original signal amplitude, harmonic amplitude, and negative-sequence component amplitude. This leads to a mixture of fault characteristics and measurement errors on the same amplitude dimension, resulting in reference drift in the diagnostic system, the possibility of false alarms, insufficient robustness in practical applications, and an inability to readily obtain accurate eccentricity angles.

[0006] Therefore, a fault diagnosis scheme for static eccentricity of permanent magnet synchronous motors is needed, which can remove error coupling at the sensing level through physical layout and initial calibration, and use dual independent information of amplitude and phase to finally output the accurate magnitude and direction of static eccentricity. Summary of the Invention

[0007] The technical problem to be solved by this invention is: for permanent magnet synchronous motors, how to utilize the amplitude-phase modulation characteristics of static eccentricity on the air gap magnetic flux signal, combined with sensor configuration and signal processing methods, to achieve highly reliable detection of static eccentricity faults, and simultaneously calculate the magnitude of the eccentricity and the eccentricity direction angle.

[0008] The principle of this invention is to decouple sensor error and fault characteristics in the signal dimension from a physical perspective through sensor spatial layout and signal analysis methods, and to directly calculate the geometric parameters of eccentricity by utilizing the dual composite characteristics of amplitude and phase.

[0009] To solve the above-mentioned technical problems, the present invention provides a technical solution implemented through the following steps:

[0010] A method for diagnosing static eccentricity faults in a permanent magnet synchronous motor includes:

[0011] Step 1: In the permanent magnet synchronous motor, select two stator slots S1 and S3 with a circumferential angle difference of 60° on the cross-section of the rotor and stator as the installation group.

[0012] Embed a [something] on the center line of the S1 slot. Group of linear Hall sensors ,exist The center line of the S7 slot, which has a circumferential angle difference of 180°, is embedded in the topographic position of the linear Hall sensor. Group of linear Hall sensors II ;

[0013] Similarly, at the center lines of the S3 slot and the S9 slot at the opposite position, respectively, are embedded Group of linear Hall sensors and Group of linear Hall sensors II ;

[0014] Step 2: Perform initial calibration and error decoupling on the permanent magnet synchronous motor based on the signal collected by the linear Hall sensor;

[0015] Step 3: When the permanent magnet synchronous motor is running normally, it enters the online monitoring mode, extracts the amplitude ratio characteristics and phase difference characteristics in real time, and determines whether to trigger the eccentricity fault warning based on the amplitude ratio characteristics and phase difference characteristics.

[0016] In the aforementioned method for diagnosing static eccentricity faults in a permanent magnet synchronous motor, in step one, the magnetic sensing surfaces of all linear Hall sensors are oriented towards the rotor center to detect radial magnetic flux, and the center of each linear Hall sensor is located at the middle of the slot height. The pins of each linear Hall sensor are connected via flexible... To introduce.

[0017] In the aforementioned method for diagnosing static eccentricity faults in a permanent magnet synchronous motor, in step two, under calibration mode, the permanent magnet synchronous motor is driven by an external driver to run at a constant speed under no-load conditions.

[0018] Synchronous acquisition Group of linear Hall sensors , Group of linear Hall sensors II , Group of linear Hall sensors , Group of linear Hall sensors II Four raw voltage signals , respectively Group voltage signal one , Group voltage signal two , Group voltage signal one , Group voltage signal two ;

[0019] After digital filtering of the four original voltage signals, the fundamental component is extracted using Fast Fourier Transform, and the results are calculated respectively. Linear Hall sensors The topological signal within the linear Hall sensor group Group fundamental phase difference and Group fundamental phase difference ;

[0020] In an ideal state of concentricity Group fundamental phase difference and Group fundamental phase difference The theoretical value is 180° electrical angle. The initial eccentricity is calculated by solving the geometric relationship. and eccentricity direction angle If the initial eccentricity If the value is less than the set value, the permanent magnet synchronous motor is considered to be a quasi-healthy benchmark;

[0021]

[0022]

[0023]

[0024] in, , They are respectively Group of linear Hall sensors , Group of linear Hall sensors The mechanical angle of installation, , They are respectively Group, The equivalent phase shift caused by eccentricity in a linear Hall sensor It is an intermediate variable.

[0025] The aforementioned method for diagnosing static eccentricity faults in permanent magnet synchronous motors is applicable to... Linear Hall sensors A set of linear Hall effect sensors is used to obtain the gain compensation coefficient through fitting calibration data. Then measure the DC offset of the output signal of the linear Hall sensor and record it as... Compensation value;

[0026] The calculated gain compensation coefficients of different groups of linear Hall sensor signals and offset compensation amount The data is stored in the processor's memory to form a calibration parameter table.

[0027] In the aforementioned method for diagnosing static eccentricity faults in a permanent magnet synchronous motor, step three involves executing the following cycle for each electrical cycle, mechanical cycle, or fixed time interval:

[0028] Read real-time raw voltage signal ,include Group voltage signal one , Group voltage signal two , Group voltage signal one , Group voltage signal two ;

[0029] The original voltage signal is compensated using calibration parameters;

[0030] Real-time extraction of amplitude ratio and phase difference features:

[0031] Within a complete mechanical cycle Group compensated voltage signal one and Group compensation voltage signal two The peak values ​​are respectively Group peak one and Group peak two Calculate the real-time amplitude ratio ;

[0032]

[0033] in, The mechanical angle for mounting the linear Hall sensor. The eccentricity direction angle, Eccentricity;

[0034] Detection Group compensated voltage signal one and Group compensation voltage signal two Each zero-crossing point from negative to positive is recorded as a timestamp one. and timestamp 2 Calculate the time difference at the zero point And based on the real-time speed of the motor Converted to electrical angle difference Then calculate the equivalent phase shift caused by eccentricity: when the number of pole pairs It is an odd number. When the extreme logarithm Even number, ;

[0035] Amplitude ratio and electrical angle difference If any indicator exceeds the preset health threshold range for an extended period of time, an eccentricity fault warning will be triggered.

[0036] In the aforementioned method for diagnosing static eccentricity faults in a permanent magnet synchronous motor, the eccentricity rate is quickly calculated using the following formula in step three. and eccentricity direction angle :

[0037]

[0038]

[0039]

[0040] in, The outer diameter of the rotor. The effective air gap length of the motor in a fully concentric state. , These are the zero-crossing points of the signals from a pair of 180° symmetrically distributed linear Hall sensors, and the installation angle of linear Hall sensor one.

[0041] The aforementioned method for diagnosing static eccentricity faults in permanent magnet synchronous motors also includes:

[0042] Step Four: When online screening triggers an alert or a regular in-depth physical examination is performed, further high-precision diagnosis is conducted, including:

[0043] At a higher sampling frequency, complete waveform data from two sets of four Hall sensors, after compensation, are continuously recorded for at least ten electrical cycles.

[0044] The recorded waveform data is then sequentially windowed, Transformation, Extraction The fundamental component information of the Hall sensor signal includes:

[0045] calculate Group compensated voltage signal one and Group compensation voltage signal two Difference in fundamental amplitude ;

[0046] If the extreme pair If it is an odd number, Group compensated voltage signal one and Group compensation voltage signal two The signals are added together, and the fundamental amplitude of the synthesized signal is obtained. ;

[0047] Direct Read Group compensated voltage signal one and Group compensation voltage signal two Phase difference of fundamental component ;

[0048] The difference in fundamental frequency amplitude The fundamental amplitude of the synthesized signal Fundamental phase difference Substituting the known motor structural parameters into the following formula, we obtain the static eccentricity. and eccentricity direction angle :

[0049]

[0050]

[0051] The motor structural parameters include the rotor outer diameter. and effective air gap length .

[0052] A static eccentricity fault diagnosis system for a permanent magnet synchronous motor includes:

[0053] Sensor module: includes multiple linear Hall sensors, which are embedded in the stator of the permanent magnet synchronous motor in a predetermined spatial geometric relationship;

[0054] Signal conditioning module: includes an operational amplifier, an anti-aliasing filter circuit, and an analog-to-digital converter connected in sequence. It is used to amplify, filter, and convert the weak voltage signal output by the Hall sensor into a digital signal;

[0055] Data diagnostic module: including embedded microprocessor or digital signal processor It is used to run the stored diagnostic program, perform initial calibration, feature extraction, model calculation based on the digital signal output by the signal conditioning module, and output the static eccentricity fault diagnosis result of the permanent magnet synchronous motor.

[0056] It also includes an output module: uploading the static eccentricity fault diagnosis results of the permanent magnet synchronous motor to a host computer or vehicle controller, wherein the diagnosis results include the static eccentricity. and eccentricity direction angle .

[0057] A static eccentricity fault diagnosis system for permanent magnet synchronous motors involves selecting two stator slots, S1 and S3, with a circumferential angle difference of 60° on the cross-sections of the rotor and stator of the permanent magnet synchronous motor as the mounting group.

[0058] Embed a [something] on the center line of the S1 slot. Group of linear Hall sensors ,exist The center line of the S7 slot, which has a circumferential angle difference of 180°, is embedded in the topographic position of the linear Hall sensor. Group of linear Hall sensors II ;

[0059] Similarly, at the center lines of the S3 slot and the S9 slot at the opposite position, respectively, are embedded Group of linear Hall sensors and Group of linear Hall sensors II .

[0060] The aforementioned static eccentricity fault diagnosis system for permanent magnet synchronous motors includes the following features during the feature extraction process:

[0061] Amplitude ratio characteristic: within one complete mechanical cycle, Group compensated voltage signal one and Group compensation voltage signal two The peak values ​​are respectively Group peak one and Group peak two Calculate the real-time amplitude ratio ;

[0062]

[0063] in, The mechanical angle for mounting the linear Hall sensor. The eccentricity direction angle, Eccentricity;

[0064] Phase difference characteristics: detection Group compensated voltage signal one and Group compensation voltage signal two Each zero-crossing point from negative to positive is recorded as a timestamp one. and timestamp 2 Calculate the time difference at the zero point And based on the real-time speed of the motor Converted to electrical angle difference Then calculate the equivalent phase shift caused by eccentricity: when the number of pole pairs It is an odd number. When the extreme logarithm Even number, .

[0065] The beneficial effects achieved by this invention are as follows: The method of this invention avoids inherent measurement errors of the sensors through initial calibration, reduces the false alarm rate caused by sensor inconsistencies and temperature drift, and provides accurate data for maintenance operations by directly calculating the eccentric displacement and eccentric direction angle from the physical model. Since dual feature extraction is based on difference and ratio calculations of physically symmetrical points, and considering the simultaneous influence of motor load changes and power supply harmonics, common-mode interference between the two opposing sensors is suppressed, ensuring the stability of diagnostic results under varying operating conditions and loads. The method of this invention does not require modifications to the permanent magnet synchronous motor topology or pole slots; the sensor layout, calibration, and diagnostic algorithms can all be embedded in an embedded chip. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the overall architecture of the static eccentricity detection system for permanent magnet synchronous motors provided in Embodiment 1 of the present invention;

[0067] Figure 2 This is a flowchart of the static eccentricity diagnosis method for permanent magnet synchronous motors provided in Embodiment 1 of the present invention.

[0068] Figure 3 This is a schematic diagram of the layout of the linear Hall sensor in the permanent magnet synchronous motor in Embodiment 1 of the present invention;

[0069] Figure 4 This is a detailed flowchart of the initial calibration and error decoupling steps in Embodiment 1 of the present invention;

[0070] Figure 5 This is a flowchart illustrating the online real-time screening steps in Embodiment 1 of the present invention.

[0071] Figure 6 This is a flowchart of the offline precise quantitative analysis steps in Embodiment 1 of the present invention.

[0072] The markings in the diagram are as follows: 1. Permanent magnet synchronous motor; 2. Stator; 3. Permanent magnet; 4. Rotor; 5. Linear Hall sensor; 6. Digital signal processor; 7. Linear Hall sensor 1 (Group A); 8. Linear Hall sensor 1 (Group B); 9. Linear Hall sensor 2 (Group A); 10. Linear Hall sensor 2 (Group B). Detailed Implementation

[0073] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0074] Example 1

[0075] like Figure 1 As shown, this embodiment provides a static eccentricity fault diagnosis system for a permanent magnet synchronous motor, including:

[0076] Sensor module: Includes multiple linear Hall sensors, model MLX90251, which are embedded in the stator of the permanent magnet synchronous motor according to a predetermined spatial geometry. The installation method of the linear Hall sensors is the same as that described below.

[0077] Signal conditioning module: including an operational amplifier, an anti-aliasing filter circuit and an analog-to-digital converter (ADC) connected in sequence, used to amplify, filter and convert the weak voltage signal output by the Hall sensor into a digital signal.

[0078] Data diagnostic module: includes an embedded microprocessor or digital signal processor (DSP), model TITMS320F28379D, which runs the stored diagnostic program. It performs all algorithms such as initial calibration, feature extraction, and model calculation based on the digital signal output by the signal conditioning module, and outputs the diagnostic results of static eccentricity fault of permanent magnet synchronous motor.

[0079] Output module: Uploads the diagnostic results to the host computer or vehicle controller via CAN bus, RS485, or Ethernet interface, or displays them on a local display screen for alarm and alert purposes. The diagnostic results include static eccentricity. and eccentricity direction angle .

[0080] Example 2

[0081] The following is combined with Figure 2 Taking a 12-slot, 5-pole fractional-slot concentrated winding surface-mounted permanent magnet synchronous motor as an example, the steps of the static eccentricity fault diagnosis method for permanent magnet synchronous motors of the present invention are described in detail.

[0082] A method for diagnosing static eccentricity faults in a permanent magnet synchronous motor includes:

[0083] Step 1: As Figure 3 As shown, a linear Hall sensor is installed in the permanent magnet synchronous motor. In the prior art, the linear Hall sensor is arranged with equal spacing or random layout. In this embodiment, a topological layout based on physical symmetry is adopted.

[0084] (1) In a permanent magnet synchronous motor, the stator is provided with a total of 12 slots. On the cross-section of the rotor and the stator, two stator slots S1 and S3 with a circumferential angle difference of 60° are selected as the mounting group.

[0085] (2) Embed a [something] on the center line of the S1 slot. Group of linear Hall sensors ,exist The center line of the S7 slot, which has a circumferential angle difference of 180°, is embedded in the topographic position of the linear Hall sensor. Group of linear Hall sensors II ;

[0086] (3) Similarly, at the center line of the S3 slot and the S9 slot at the opposite position, respectively, embed Group of linear Hall sensors and Group of linear Hall sensors II ;

[0087] (4) During installation, the magnetic sensing surfaces of all linear Hall sensors should face the center of the rotor to detect radial magnetic flux, and the center of each linear Hall sensor should be located in the middle of the slot height. The pins of each linear Hall sensor are led out through a flexible PCB.

[0088] After installation, Group of linear Hall sensors and Group of linear Hall sensors II , Group of linear Hall sensors and Group of linear Hall sensors II These constitute two pairs of physically symmetrical observation points. When static eccentricity occurs, the changes in the air gap length of the rotor relative to the two points are complementary, with one increasing and the other decreasing. This facilitates the direct extraction of differential and ratio characteristics and avoids uncertain installation errors.

[0089] Step 2: Perform initial calibration and error decoupling on the permanent magnet synchronous motor based on the signal collected by the linear Hall sensor;

[0090] like Figure 4 As shown, the purpose of this step is to establish a clean signal reference after the permanent magnet synchronous motor leaves the factory or is installed, so as to improve the accuracy of static eccentricity fault diagnosis.

[0091] In calibration mode, the permanent magnet synchronous motor is driven by an external driver to run at a constant speed under no-load conditions, including:

[0092] (1) Data acquisition: synchronous acquisition Group of linear Hall sensors , Group of linear Hall sensors II , Group of linear Hall sensors , Group of linear Hall sensors II Four raw voltage signals , respectively Group voltage signal one , Group voltage signal two , Group voltage signal one , Group voltage signal two ;

[0093] (2) Phase analysis to determine initial eccentricity: After digital filtering of the four original voltage signals, the fundamental component is extracted using high-precision spectrum analysis (FFT), and the phase is calculated respectively. Linear Hall sensors The topological signal within the linear Hall sensor group Group fundamental phase difference and Group fundamental phase difference In this embodiment, under ideal concentric conditions, a 10-pole motor is used, with a pole pair count of [missing information]. , is an odd number Group fundamental phase difference and Group fundamental phase difference The theoretical value is 180° electrical angle, and the phase deviation reflects the initial eccentricity introduced by manufacturing and assembly. The initial eccentricity can be calculated by solving the geometric relationships. and eccentricity direction angle If the initial eccentricity If the value is less than the set value, such as <0.01 mm, the permanent magnet synchronous motor is considered to be a quasi-healthy benchmark.

[0094]

[0095]

[0096]

[0097] in, , They are respectively Group of linear Hall sensors , Group of linear Hall sensors The mechanical angle of installation, , They are respectively Group, The equivalent phase shift caused by eccentricity in a linear Hall sensor These are intermediate variables used in the calculation of the above formula.

[0098] (3) Sensor fixed error separation: Since the initial eccentricity caused by manufacturing is known and very small, theoretically Group, The fundamental amplitudes of the topological signals within the same group should be equal. The actual measured amplitude differences mainly originate from the gain error of the linear Hall sensor itself. And the sensitivity difference caused by installation deviation, for Linear Hall sensors A set of linear Hall effect sensors is used to obtain the gain compensation coefficient through fitting calibration data. Then measure the DC offset of the output signal of the linear Hall sensor and record it as... Compensation value.

[0099] (4) Establish a compensation lookup table: calculate the gain compensation coefficients of the linear Hall sensor signals of different groups. and offset compensation amount The calibration parameters are stored in the processor's non-volatile memory to form a calibration parameter table.

[0100] Step 3: Conduct online real-time screening; such as Figure 5 As shown, when the permanent magnet synchronous motor is running normally, it enters the online monitoring mode and executes the following cycle for each electrical cycle, mechanical cycle, or fixed time interval:

[0101] (1) Signal compensation: Read the real-time raw voltage signal ,include Group voltage signal one , Group voltage signal two , Group voltage signal one , Group voltage signal two ;

[0102] Compensation is performed using calibration parameters: As the input signal for subsequent algorithms, the sensor's own error has been eliminated.

[0103] (2) Real-time extraction of dual features, including:

[0104] Amplitude ratio characteristic: within one complete mechanical cycle, Group compensated voltage signal one and Group compensation voltage signal two The peak values ​​are respectively Group peak one and Group peak two Calculate the real-time amplitude ratio ;

[0105]

[0106] in, The mechanical angle for mounting the linear Hall sensor. The eccentricity direction angle, This is the eccentricity rate.

[0107] Phase difference characteristics: detection Group compensated voltage signal one and Group compensation voltage signal two Each zero-crossing point from negative to positive is recorded as a timestamp one. and timestamp 2 Calculate the time difference at the zero point And based on the real-time speed of the motor Converted to electrical angle difference Based on this, the equivalent phase shift caused by eccentricity can be calculated. polar number It is an odd number; polar number It is an even number.

[0108] For extreme pairs , , It is the equivalent phase shift caused by eccentricity.

[0109] (3) Threshold discrimination and primary warning: The amplitude ratio and electrical angle difference The data is compared with a preset health threshold range, which is determined through statistics or simulation. If any indicator continues to exceed the limit within a set time, an eccentricity fault warning is immediately triggered, and an alarm signal is issued through the output module.

[0110] Meanwhile, the eccentricity can be quickly calculated using the following formula. and eccentricity direction angle :

[0111]

[0112]

[0113]

[0114] in, The outer diameter of the rotor. The effective air gap length of the motor in a fully concentric state. , These are the zero-crossing points of the signals from a pair of 180° symmetrically distributed linear Hall sensors, and the installation angle of linear Hall sensor one.

[0115] Example 3

[0116] Based on the technical solution of Embodiment 2, the static eccentricity fault diagnosis method for a permanent magnet synchronous motor in this embodiment further includes:

[0117] Step 4: Perform offline, precise quantitative analysis. For example... Figure 6 As shown, when online screening triggers an alert or a regular in-depth physical examination is performed, further high-precision diagnosis is conducted, including:

[0118] High-fidelity data recording: At least ten electrical cycles of complete waveform data from two sets of four Hall sensors, after compensation, are continuously recorded at a higher sampling frequency, which may be 10kHz.

[0119] Precise spectrum analysis: The recorded waveform data is sequentially windowed and subjected to FFT transformation to extract... The fundamental component information of the Hall sensor signal includes:

[0120] Fundamental amplitude difference :calculate Group compensated voltage signal one and Group compensation voltage signal two Difference in fundamental amplitude ;

[0121] fundamental amplitude of the synthesized signal If the extreme logarithm If it is an odd number, Group compensated voltage signal one and Group compensation voltage signal two The signals are added together, and the fundamental amplitude of the synthesized signal is obtained. ;

[0122] Fundamental phase difference Direct reading Group compensated voltage signal one and Group compensation voltage signal two Phase difference of fundamental component .

[0123] Model analysis and parameter calculation: fundamental amplitude difference The fundamental amplitude of the synthesized signal Fundamental phase difference Substituting the known motor structural parameters into the following formula, we obtain the static eccentricity. and eccentricity direction angle :

[0124]

[0125] .

[0126] The motor structural parameters include the rotor outer diameter. and effective air gap length .

[0127] The method of this invention can operate reliably under any off-center orientation, avoiding diagnostic blind spots, as explained below. Theoretically, if only a single set of topological sensors is used, such as… Group, when the static eccentricity direction angle Mechanical angle of installation with linear Hall sensor When certain geometric relationships are met, single-dimensional diagnostic indicators may experience decreased sensitivity or diagnostic blind spots:

[0128] Scenario 1: When At this time, the eccentric direction is perpendicular to the line connecting the two sensors. The air gap changes are the same at both Hall sensors, resulting in no significant difference in the fundamental amplitude of their signals, and the amplitude ratio is... The phase difference between the two signals will approach 1, but the phase difference between them will reach its maximum.

[0129] Scenario 2: When Or at 180°, the eccentric direction is consistent with the direction of the line connecting the Hall sensors in this group. At this time, the air gap changes at the two Hall sensors are completely complementary, and their signal amplitude difference reaches its maximum. However, the zero-crossing point of the magnetic field moves symmetrically, causing the signal phase difference to tend to zero or a negligible small fixed value.

[0130] The present invention eliminates the above-mentioned potential problems through the following solution:

[0131] Employing at least two sets of Toh Hall sensor arrays spatially offset by 60° mechanical angles, such as Groups and Group. This design ensures that for any possible eccentric direction, , It is impossible for two sets of Hall sensors to simultaneously enter the same special situation described above. For example, when the eccentric direction makes... When the group is in situation one, for For a group, the geometric relation must be far from case one, thus ensuring The amplitude difference index of the group has high sensitivity; at the same time, The phase difference index of the two sets of sensors is at a high sensitivity level at this point. The two sets of sensors form a natural and complementary sensitivity matrix in both amplitude and phase dimensions.

[0132] In the offline precise quantification phase, multi-dimensional data from all sensor groups are simultaneously collected and jointly processed, including... , The amplitude difference, combined amplitude, and phase difference of the groups are calculated and substituted into a unified analytical model for fusion and solution. This analytical model is a system of equations with multiple constraints. When a certain characteristic quantity of a group of Hall sensors has a weak signal due to the aforementioned geometric relationship, strong characteristic quantities from other groups or other dimensions will automatically compensate through the constraints of the equation system, ensuring the stability and accuracy of the entire system solution. Therefore, the final eccentricity... and eccentricity direction angle It is determined by the information from all sensors, and the result is not affected by the sensitivity change of any single sensor at a specific moment.

[0133] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art to the technical solution disclosed in the present invention after seeing the technical solution disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for diagnosing static eccentricity faults in a permanent magnet synchronous motor, characterized in that, include: Step 1: In the permanent magnet synchronous motor, select two stator slots S1 and S3 with a circumferential angle difference of 60° on the cross-section of the rotor and stator as the installation group. Embedded on the center line of the S1 slot Group of linear Hall sensors ,exist The center line of the S7 slot of the linear Hall sensor is embedded in the topographic position. Group of linear Hall sensors II The aforementioned positions are those with a circumferential angle difference of 180°. Embedded at the center lines of the S3 slot and the S9 slot at the opposite top position respectively Group linear Hall sensor - H b1 and Group of linear Hall sensors II ; Step 2: Perform initial calibration and error decoupling on the permanent magnet synchronous motor based on the signal collected by the linear Hall sensor; Step 3: When the permanent magnet synchronous motor is running normally, it enters the online monitoring mode, extracts the amplitude ratio characteristics and phase difference characteristics in real time, and determines whether to trigger the eccentricity fault warning based on the amplitude ratio characteristics and phase difference characteristics.

2. The method for diagnosing static eccentricity faults in a permanent magnet synchronous motor according to claim 1, characterized in that, In step one, the magnetic sensing surfaces of all linear Hall sensors are oriented towards the rotor center to detect radial magnetic flux, and the center of each linear Hall sensor is located at the middle of the slot height. The pins of each linear Hall sensor are connected via flexible... To introduce.

3. The method for diagnosing static eccentricity faults in a permanent magnet synchronous motor according to claim 1, characterized in that, In step two, in calibration mode, the permanent magnet synchronous motor is driven by an external driver to run at a constant speed under no-load conditions; Synchronous acquisition Group of linear Hall sensors , Group of linear Hall sensors II , Group of linear Hall sensors , Group of linear Hall sensors II Four raw voltage signals , respectively Group voltage signal one , Group voltage signal two , Group voltage signal one , Group voltage signal two ; After digital filtering of the four original voltage signals, the fundamental component is extracted using Fast Fourier Transform, and the results are calculated respectively. Linear Hall sensors The topological signal within the linear Hall sensor group Group fundamental phase difference and Group fundamental phase difference ; The initial eccentricity is calculated by solving the geometric relationships. and eccentricity direction angle If the initial eccentricity If the value is less than the set value, the permanent magnet synchronous motor is considered to be in a quasi-healthy state; ； ； ； in, , They are respectively Group of linear Hall sensors , Group of linear Hall sensors The mechanical angle of installation, , They are respectively Group, The equivalent phase shift caused by eccentricity in a linear Hall sensor It is an intermediate variable.

4. The method for diagnosing static eccentricity faults in a permanent magnet synchronous motor according to claim 3, characterized in that, for Linear Hall sensors A set of linear Hall effect sensors is used to obtain the gain compensation coefficient through fitting calibration data. Then measure the DC offset of the output signal of the linear Hall sensor and record it as... Compensation value; The calculated gain compensation coefficients of different groups of linear Hall sensor signals and offset compensation amount The data is stored in the processor's memory to form a calibration parameter table.

5. The method for diagnosing static eccentricity faults in a permanent magnet synchronous motor according to claim 1, characterized in that, In step three, the following cycle is executed for each electrical cycle, mechanical cycle, or fixed time interval: Read real-time raw voltage signal ,include Group voltage signal one , Group voltage signal two , Group voltage signal one , Group voltage signal two ; The original voltage signal is compensated using calibration parameters; Real-time extraction of amplitude ratio and phase difference features, including: Amplitude ratio characteristic: within one complete mechanical cycle, Group compensated voltage signal and Group compensation voltage signal two The peak values ​​are respectively Group peak one and Group peak two Calculate the real-time amplitude ratio ; ； in, The mechanical angle for mounting the linear Hall sensor. The eccentricity direction angle, Eccentricity; Phase difference characteristics: detection Group compensated voltage signal and Group compensation voltage signal two Each zero-crossing point from negative to positive is recorded as a timestamp one. and timestamp 2 Calculate the time difference at the zero point And based on the real-time speed of the motor Converted to electrical angle difference Then calculate the equivalent phase shift caused by eccentricity: when the number of pole pairs It is an odd number. When the extreme logarithm Even number, ; Amplitude ratio and electrical angle difference If any indicator exceeds the preset health threshold range for an extended period of time, an eccentricity fault warning will be triggered.

6. The method for diagnosing static eccentricity faults in a permanent magnet synchronous motor according to claim 1, characterized in that, In step three, the eccentricity is calculated using the following formula. and eccentricity direction angle : ； ； ； in, The outer diameter of the rotor. The effective air gap length of the motor in a fully concentric state. , These are the zero-crossing points of the signals from a pair of 180° symmetrically distributed linear Hall sensors, and the installation angle of linear Hall sensor one.

7. The method for diagnosing static eccentricity faults in a permanent magnet synchronous motor according to claim 1, characterized in that, Also includes: Step Four: When online screening triggers an alert or a regular in-depth physical examination is performed, further high-precision diagnosis is conducted, including: At a higher sampling frequency, complete waveform data from two sets of four Hall sensors, after compensation, are continuously recorded for at least ten electrical cycles. The recorded waveform data is then sequentially windowed, Transformation, Extraction The fundamental component information of the Hall sensor signal includes: calculate Group compensated voltage signal and Group compensation voltage signal two Difference in fundamental amplitude ; If the extreme pair If it is an odd number, Group compensated voltage signal and Group compensation voltage signal two The signals are added together, and the fundamental amplitude of the synthesized signal is obtained. ; Direct Read Group compensated voltage signal and Group compensation voltage signal two Phase difference of fundamental component ; The difference in fundamental frequency amplitude The fundamental amplitude of the synthesized signal Fundamental phase difference Substituting the known motor structural parameters into the following formula, we obtain the static eccentricity. and eccentricity direction angle : ； ； The motor structural parameters include the rotor outer diameter. and effective air gap length .

8. A static eccentricity fault diagnosis system for a permanent magnet synchronous motor, characterized in that, include: Sensor module: includes multiple linear Hall sensors, which are embedded in the stator of the permanent magnet synchronous motor in a predetermined spatial geometric relationship; Signal conditioning module: includes an operational amplifier, an anti-aliasing filter circuit, and an analog-to-digital converter connected in sequence. It is used to amplify, filter, and convert the weak voltage signal output by the Hall sensor into a digital signal; Data diagnostic module: including embedded microprocessor or digital signal processor It is used to run the stored diagnostic program, to perform initial calibration, feature extraction, model calculation based on the digital signal output by the signal conditioning module, and to output the static eccentricity fault diagnosis result of the permanent magnet synchronous motor. It also includes an output module: uploading the static eccentricity fault diagnosis results of the permanent magnet synchronous motor to a host computer or vehicle controller, wherein the diagnosis results include the static eccentricity. and eccentricity direction angle .

9. A static eccentricity fault diagnosis system for a permanent magnet synchronous motor according to claim 1, characterized in that, In a permanent magnet synchronous motor, two stator slots, S1 and S3, with a circumferential angle difference of 60°, are selected as mounting groups on the cross-sections of the rotor and stator. Embed a [something] on the center line of the S1 slot. Group of linear Hall sensors ,exist The center line of the S7 slot, which has a circumferential angle difference of 180°, is embedded in the topographic position of the linear Hall sensor. Group of linear Hall sensors II ; Embedded at the center lines of the S3 slot and the S9 slot at the opposite top position respectively Group of linear Hall sensors and Group of linear Hall sensors II .

10. A static eccentricity fault diagnosis system for a permanent magnet synchronous motor according to claim 1, characterized in that, The feature extraction process includes: Amplitude ratio characteristic: within one complete mechanical cycle, Group compensated voltage signal and Group compensation voltage signal two The peak values ​​are respectively Group peak one and Group peak two Calculate the real-time amplitude ratio ; ； in, The mechanical angle for mounting the linear Hall sensor. The eccentricity direction angle, Eccentricity; Phase difference characteristics: detection Group compensated voltage signal and Group compensation voltage signal two Each zero-crossing point from negative to positive is recorded as a timestamp one. and timestamp 2 Calculate the time difference at the zero point And based on the real-time speed of the motor Converted to electrical angle difference Then calculate the equivalent phase shift caused by eccentricity: when the number of pole pairs It is an odd number. When the extreme logarithm Even number, .

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