Motor rotor and rotor vibration control method

Abstract

The invention relates to the technical field of motor equipment, and discloses a motor rotor and a rotor vibration control method, the motor rotor is used for being installed in a stator of a motor, and the motor rotor comprises an iron core and a permanent magnet; the number of the iron cores is multiple, and the multiple iron cores are sequentially stacked together. A mounting hole is formed in the center of the iron core, and a rotating shaft is fixed in the mounting hole in a penetrating manner; the iron core is provided with a plurality of magnetic slots; the multiple magnetic grooves are distributed in the circumferential direction of the mounting hole in a surrounding mode. The number of the permanent magnets is in one-to-one correspondence with the number of the magnetic slots; the permanent magnets are clamped in the magnetic slots; the outer circle of the iron core corresponding to the interval area of every two adjacent magnetic grooves is a plane. Electromagnetic noise and vibration of the motor are obviously reduced from the source, and running quietness is improved. And the torque pulse generated when the rotor rotates is reduced.

Description

Technical Field

[0001] This application relates to the field of motor equipment technology, and specifically to a motor rotor and a rotor vibration control method. Background Technology

[0002] Built-in permanent magnet synchronous motors (IPMSMs) have become core components in electric vehicles, industrial servo systems, and other fields due to their high power density, high efficiency, and wide speed range. The core performance of the motor largely depends on the design and manufacturing of its rotor.

[0003] Traditional built-in permanent magnet synchronous motor rotors are typically made of stacked stamped silicon steel sheets, with grooves punched into the sheets for embedding permanent magnets. The arrangement of these grooves (such as V-shape, straight line, etc.) determines the rotor's magnetic circuit structure, which in turn affects the motor's key electromagnetic properties such as saliency ratio and reluctance torque.

[0004] When the rotor rotates at high speed, the presence of the permanent magnet magnetic field on its outer circular surface will generate abundant spatial force waves and electromagnetic harmonics through interaction with the stator. These harmonics are the main source of electromagnetic noise (such as howling) and vibration in the motor. In particular, when the outer circle of the rotor is a standard cylindrical surface, the uneven distribution of the magnetic field on this surface will aggravate the electromagnetic excitation force of a certain order, thereby amplifying the noise and vibration. Summary of the Invention

[0005] This application provides a motor rotor and a rotor vibration control method to solve the above-mentioned problems.

[0006] In one embodiment, a motor rotor is provided for mounting within the stator of a motor, comprising: The iron core is a plurality of iron cores stacked together in sequence; a mounting hole is provided at the center of each iron core, and a rotating shaft is inserted and fixed in the mounting hole; each iron core has a plurality of magnetic grooves; the plurality of magnetic grooves are distributed around the mounting hole in a circumferential direction. The permanent magnets are arranged in a one-to-one correspondence with the number of magnetic slots; the permanent magnets are engaged in the magnetic slots; the outer circle of the iron core corresponding to the area between two adjacent magnetic slots is planar.

[0007] The two adjacent iron cores are stacked together and sealed tightly. The iron cores are made of silicon steel sheets. The rotating shaft is rotatably connected to the stator.

[0008] The two adjacent iron cores are sealed together in a laminated manner, which means that the iron cores achieve an extremely high degree of fit during the lamination process, virtually eliminating the gaps between the cores. This not only greatly enhances the overall structural strength and rigidity of the rotor, enabling it to withstand higher speeds and centrifugal forces without deformation, but also effectively reduces inter-core contact resistance, lowers eddy current losses, thereby improving motor efficiency and heat dissipation performance.

[0009] The core is made of silicon steel sheets, a mature and cost-effective material choice. Designing the outer circular portion as a flat surface may be simpler to process than machining a high-precision, full arc under certain conditions, helping to control manufacturing costs. The entire solution is based on a mature lamination process, requiring no introduction of complex new production procedures, making it easy to industrialize and highly practical and economical.

[0010] In one embodiment, the iron core has multiple cooling channels; the middle of the rotating shaft has a main channel for coolant to flow in; the cooling channels are connected to the main channel through a first connecting channel; the cooling channels are connected to the magnetic groove through a second connecting channel; and both ends of the magnetic groove have openings that communicate with the outer circle of the iron core.

[0011] Specifically, the permanent magnet is engaged with the magnetic groove, but there is a gap between the inner wall of the magnetic groove and the permanent magnet, allowing coolant to flow over the surface of the permanent magnet.

[0012] Both the first and second connecting channels are formed by stacking and connecting slots opened in 3-5 adjacent iron cores.

[0013] In one embodiment, one end of the rotating shaft is rotatably connected to an oil supply connector, and the rotating shaft and the oil supply connector are sealed together; the oil supply connector is connected to the main channel; the oil supply connector is used to communicate with external cooling oil.

[0014] Specifically, the oil supply connector is connected to the shaft via a bearing.

[0015] In one embodiment, a reflux groove is provided on the lower part of the inner wall of the stator.

[0016] In one embodiment, the inner wall of the stator has a plurality of racks for winding electromagnetic coils; the plurality of racks are distributed circumferentially at intervals along the inner wall of the stator; and a sealing strip is directly fixedly connected to two adjacent racks.

[0017] The reflux groove is located on the sealing strip.

[0018] In one embodiment, the stator is provided with multiple cooling circuits; each cooling circuit includes a water outlet passage and a return passage; each return passage passes through one of the multiple racks respectively.

[0019] Specifically, the oil supply connector is connected to an oil pump, which is located inside the cooling oil tank. The cooling oil tank is connected to a cooler, and the cooling oil that returns after cooling (the cooling oil in the return path and the return tank) all flows into the cooling oil tank after passing through the cooler.

[0020] In one embodiment, the sealing strip is made of a magnetic material.

[0021] Specifically, magnetic adhesive / epoxy resin is used for sealing.

[0022] The magnetic filler portion "bridges" the slot, increasing the equivalent permeability of that area. This smooths out the permeability difference between the stator teeth and the slot.

[0023] As the rotor rotates, the change in air gap magnetic permeability decreases. The change in the "attraction" felt by the permanent magnet also weakens, effectively suppressing cogging torque and thus reducing overall torque pulsation.

[0024] In one embodiment, the magnetic groove is V-shaped, and two permanent magnets are spaced apart in each magnetic groove.

[0025] The two ends of the magnetic groove are hollow.

[0026] In one embodiment, a vibration state observer for detecting the vibration of the rotating shaft is fixedly mounted on the stator; the vibration state observer is electrically connected to the controller; the stator is electrically connected to the controller.

[0027] In one embodiment, this application provides a rotor vibration control method, comprising the following steps: Identify the vibration source based on the vibration signal from the vibration state observer; The harmonic frequencies of the vibration source are classified into vibration conditions of electromagnetic torque pulsation or vibration conditions of mass imbalance. The harmonics corresponding to the vibration conditions of the electromagnetic torque pulsation are input into the proportional resonant controller, which generates a reverse compensation current and inputs it into the stator to cancel the torque pulsation at that frequency. The harmonics classified as corresponding to the vibration conditions of mass imbalance are input into the suppression model, and the corresponding electromagnetic force compensation current is output and input into the stator to counteract the unbalanced force.

[0028] The beneficial effects of this application are: The outer circle of the iron core corresponding to the area between two adjacent magnetic slots is planar. This design changes the traditional continuous cylindrical rotor outer circle to an approximately polygonal contour composed of multiple planes. This structure can effectively modulate the distribution of the air gap magnetic field, smooth the magnetic flux density curve, sinusoidalize the rotor's magnetic field, reduce the amplitude of the electromagnetic excitation force acting on the stator, and in particular, weaken the key order harmonics that cause noise. This significantly reduces the electromagnetic noise and vibration of the motor at its source, improving operational quietness. It also reduces the torque pulses generated during rotor rotation.

[0029] This rotor optimizes mechanical and acoustic performance while fully retaining the core advantages of an integrated permanent magnet synchronous motor. The structure of the permanent magnet embedded inside the iron core ensures a high saliency rate, fully utilizing reluctance torque to achieve high power density and high efficiency operation. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the cross-sectional structure of a magnetic levitation motor in one embodiment of this application; Figure 2 This is a schematic diagram of the rotor longitudinal section structure in one embodiment of this application; Figure 3 yes Figure 1 A schematic diagram of the cross-sectional structure at point A in the diagram; Figure 4 yes Figure 1 Schematic diagram of the cross-sectional structure at point B in the diagram; Figure 5 This is a flowchart of rotor vibration control in one embodiment of this application; Labels for each item in the figure: 1. Stator; 11. Return channel; 12. Rack; 13. Sealing strip; 14. Water outlet passage; 15. Return passage; 2. Iron core; 21. Mounting hole; 22. Shaft; 23. Magnetic groove; 24. Cooling channel; 25. Main channel; 26. First connecting channel; 27. Second connecting channel; 28. Opening; 3. Permanent magnet; 4. Oil supply connector. Detailed Implementation

[0032] The specific embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application. Similarly, the following examples are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] This application proposes improvements and innovations, and presents the following embodiments.

[0039] In some implementations, please refer to Figures 1 to 5 A motor rotor is provided for mounting within the stator 1 of a motor, comprising: There are multiple iron cores 2, which are stacked together in sequence; a mounting hole 21 is opened at the center of the iron core 2, and a rotating shaft 22 is inserted and fixed in the mounting hole 21; the iron core 2 has multiple magnetic grooves 23; the multiple magnetic grooves 23 are distributed around the mounting hole 21 in a circumferential direction. The number of permanent magnets 3 corresponds one-to-one with the number of magnetic slots 23; the permanent magnets 3 are locked in the magnetic slots 23; the outer circle of the iron core 2 corresponding to the area between two adjacent magnetic slots 23 is planar.

[0040] The two adjacent iron cores 2 are stacked together and sealed together. The iron cores 2 are made of silicon steel sheets. The rotating shaft 22 is rotatably connected to the stator 1.

[0041] The outer circle of the iron core 2 corresponding to the area between two adjacent magnetic slots 23 is planar. This design changes the traditional continuous cylindrical rotor outer circle to an approximately polygonal contour composed of multiple planes. This structure can effectively modulate the distribution of the air gap magnetic field, smooth the magnetic flux density curve, make the rotor's magnetic field sinusoidal, reduce the amplitude of the electromagnetic excitation force acting on the stator 1, and in particular, weaken the key order harmonics that cause noise, thereby significantly reducing the electromagnetic noise and vibration of the motor from the source and improving the quietness of operation. It also reduces the torque pulses generated when the rotor rotates.

[0042] While optimizing mechanical and acoustic performance, this rotor fully retains the core advantages of an integrated permanent magnet synchronous motor. The structure of the permanent magnet 3 embedded inside the iron core 2 ensures that it has a high saliency ratio, which can make full use of reluctance torque and achieve high power density and high efficiency operation.

[0043] Specifically, the outer circle of the iron core 2 corresponding to the area between two adjacent magnetic slots 23 is planar. That is, when manufacturing the iron core, this position is directly cut into a plane, and this plane intersects the outer circle of the iron core at a large angle. Alternatively, the angle between the outer circle of the iron core and this plane can be transitioned by an arc, that is, the angle where the plane intersects with the outer circle of the iron core is rounded.

[0044] like Figure 3 As shown in the table, the dashed lines represent the outer diameter of the iron core. The following table shows the results of the experiments conducted in this application: performance First scenario The second scenario The third scenario No-load back EMF 1.02 0.99 1 average torque 1.04 1.00 1 Torque ripple 2.17 1.49 1 Cogging torque 2.00 3.03 1 As shown in the table above, "Case 1" indicates that the outer circle of the iron core is cylindrical; "Case 2" indicates that the outer circle of the iron core 2 corresponding to the area between two adjacent magnetic slots 23 is planar, and this planar plane intersects the outer circle of the iron core at a large angle. "Case 2" indicates that the angle between the plane and the outer circle of the iron core in Case 2 is rounded. In terms of performance comparison, the comparison is based on Case 3, that is, Case 3 has a no-load back EMF, average torque, torque ripple, and cogging torque performance of 1. Per-unit values ​​are used to represent the performance of the other two motors.

[0045] As shown in the table above, the torque fluctuations in the third and second cases are smaller than those in the first case (the greater the torque fluctuation, the greater the vibration generated when the rotor rotates). Overall, the performance of the third case is superior to the other two cases in all aspects.

[0046] The fact that the outer circle of the iron core 2 corresponding to the area between two adjacent magnetic slots 23 is planar can effectively modulate the distribution of the air gap magnetic field, smooth the magnetic flux density curve, make the magnetic field of the rotor sinusoidal, and reduce the amplitude of the electromagnetic excitation force acting on the stator 1.

[0047] The two adjacent iron cores 2 are sealed together, which means that the two iron cores achieve an extremely high degree of fit during the stacking process, almost eliminating the gap between the cores. This not only greatly enhances the overall structural strength and rigidity of the rotor, enabling it to withstand higher speeds and centrifugal forces without deformation, but also effectively reduces the contact resistance between the cores, lowers eddy current losses, thereby improving motor efficiency and heat dissipation performance.

[0048] Core 2 is made of silicon steel sheets, a mature and cost-effective material choice. Designing the outer circular portion as a flat surface may be simpler than machining a high-precision, full arc under certain processing methods, helping to control manufacturing costs. The entire solution is based on a mature lamination process, requiring no introduction of complex new production procedures, facilitating industrial-scale manufacturing, and demonstrating high practicality and economic efficiency.

[0049] In one embodiment, the iron core 2 has a plurality of cooling channels 24; the middle of the rotating shaft 22 has a main channel 25 for coolant to flow in; the cooling channels 24 and the main channel 25 are connected through a first connecting channel 26; the cooling channels 24 are connected to the magnetic groove 23 through a second connecting channel 27; and both ends of the magnetic groove 23 have openings 28 that communicate with the outer circle of the iron core 2.

[0050] The coolant flows through the main channel 25, the first connecting channel 26, the cooling channel 24, and the second connecting channel 27, ultimately passing over the surface of the permanent magnet 3. This directly carries away the large amount of heat generated by the permanent magnet 3 during high-speed operation, effectively preventing the permanent magnet 3 from demagnetizing due to high temperatures and ensuring the high-temperature performance and reliability of the motor. It also reduces rotational vibration problems caused by rotor overheating and bending deformation.

[0051] Specifically, the permanent magnet 3 is engaged with the magnetic groove 23, but there is a gap between the inner wall of the magnetic groove 23 and the permanent magnet 3, allowing coolant to flow over the surface of the permanent magnet 3.

[0052] Both the first connecting channel 26 and the second connecting channel 27 are formed by stacking and connecting 3-5 adjacent slots opened in the iron core 2. The first and second connecting channels 27 are composed of slots of stacked iron core 2, which eliminates the need for additional complex drilling processes. While realizing complex internal cooling oil circuits, it perfectly inherits the advantages of the stacking process and simplifies the manufacturing process.

[0053] Active cooling of the permanent magnet 3 is a key technology for maintaining the continuous output of the motor's peak power and preventing performance degradation. It is particularly suitable for high-performance applications such as electric vehicle drives and high-speed electric spindles.

[0054] In one embodiment, one end of the rotating shaft 22 is rotatably connected to an oil supply connector 4, and the rotating shaft 22 and the oil supply connector 4 are sealed together; the oil supply connector 4 is connected to the main channel 25; the connector is used to communicate with external cooling oil.

[0055] The external cooling source is dynamically connected to the main channel 25 inside the rotating shaft 22 by the oil supply connector 4, which ensures that the coolant energy flows in continuously, providing the rotor with continuous and stable cooling capacity, enabling the motor to operate under high load for a long time.

[0056] The sealed connection design between the rotating shaft 22 and the oil supply connector 4 effectively prevents coolant leakage, ensuring the efficiency of the cooling system and avoiding the risk of failure caused by liquid entering the motor air gap or bearings.

[0057] Specifically, the oil supply connector 4 is connected to the rotating shaft 22 via a bearing.

[0058] In one embodiment, a return groove 11 is provided on the lower part of the inner wall of the stator 1.

[0059] The coolant flowing out from the opening 28 of the rotor magnetic slot 23 is thrown to the inner wall of the stator 1 under the action of centrifugal force. The design of the return groove 11 can effectively collect the used hot oil and provide a path for it to return to the cooling system for heat dissipation, thus avoiding the accumulation of coolant inside the motor.

[0060] This design integrates the rotor's cooling system with the external cooling circuit into a complete unit, improving the efficiency and reliability of the entire thermal management system.

[0061] In one embodiment, the inner wall of the stator 1 has a plurality of racks 12 for winding electromagnetic coils; the plurality of racks 12 are distributed circumferentially along the inner wall of the stator 1; and two adjacent racks 12 are directly fixedly connected to a sealing strip 13.

[0062] The sealing strip 13 not only serves to physically guide and seal the coolant (in conjunction with the return groove 11), but also reduces the amount of coolant seeping into the electromagnetic coil, thus preventing it from affecting the normal operation of the electromagnetic coil.

[0063] Specifically, the cooling oil is a high-temperature resistant and high-insulation synthetic cooling oil, such as ester oil, which can directly contact the stator winding 1 and the rotor magnets, and its cooling efficiency is much higher than that of indirect water cooling.

[0064] In one embodiment, the sealing strip 13 is made of a magnetic material.

[0065] Specifically, magnetic adhesive / epoxy resin is used as the sealing material for the sealing strip 13.

[0066] The magnetic filler (sealing strip 13) partially "bridges" the slot, increasing the equivalent permeability of the area. This smooths out the permeability difference between stator tooth 1 and the slot.

[0067] As the rotor rotates, the change in air gap magnetic permeability decreases. The change in "attraction" felt by the permanent magnet 3 also weakens, thus effectively suppressing cogging torque and reducing overall torque pulsation.

[0068] The use of magnetically conductive materials (such as magnetic epoxy resin) also brings electromagnetic benefits. The magnetically conductive sealing strip 13 can smooth the magnetic permeability changes at the slot of the stator 1, significantly reducing the cogging torque, thereby reducing the torque pulsation and electromagnetic vibration noise of the motor from the source, and improving the smoothness and quietness of the motor operation.

[0069] The return groove 11 is formed on the sealing strip 13. This avoids the problem of forming the confluence groove on the stator 1 rack 12, which is difficult to form and can easily change the magnetic field distribution of the rack 12, increasing the vibration excitation source.

[0070] In one embodiment, the stator 1 has multiple cooling circuits; the cooling circuits include a water outlet passage 14 and a return passage 15; each return passage 15 passes through multiple racks 12 respectively.

[0071] A cooling circuit is set up for the stator winding 1, which can efficiently dissipate heat from the two major heat sources of the motor at the same time, ensuring the thermal safety of the motor under extreme operating conditions.

[0072] The external circulation system, consisting of an oil pump and a cooler, forces the recovered hot oil to cool, maintaining the coolant at a low temperature and ensuring the continuous high efficiency of the entire cooling system. This provides a solid foundation for the motor's power density and overload capacity.

[0073] Specifically, the oil supply connector 4 is connected to an oil pump, which is located inside the cooling oil tank. The cooling oil tank is connected to a cooler. The cooling oil that returns after cooling (the cooling oil in the return path 15 and the return tank 11) all flows into the cooling oil tank after passing through the cooler.

[0074] In one embodiment, the magnetic groove 23 is V-shaped, and two permanent magnets 3 are arranged at intervals in each magnetic groove 23.

[0075] Both ends of the magnetic groove 23 are hollow.

[0076] The V-groove 23 is a classic design for built-in permanent magnet motors. It can make full use of magnetic reluctance torque, thereby outputting greater torque under the same volume and current, and improving the power and torque density of the motor.

[0077] The hollow design at both ends of the magnetic groove 23 provides a smooth path for the coolant to flow over the surface of the permanent magnet 3 and be smoothly ejected, which is a key structural guarantee for the realization of the function of the internal cooling channel 24 of the rotor.

[0078] In one embodiment, a vibration state observer for detecting the vibration of the rotating shaft 22 is fixedly mounted on the stator 1; the vibration state observer is electrically connected to the controller; the stator 1 is electrically connected to the controller.

[0079] The vibration state observer provides the "eyes" to sense minute vibrations that cannot be directly measured in real time, thus providing a data foundation for the controller to better actively suppress vibrations.

[0080] In one embodiment, this application provides a rotor vibration control method, comprising the following steps: S1. Identify the vibration source based on the vibration signal from the vibration state observer; S2. Classify the harmonic frequencies of the vibration source into vibration conditions of electromagnetic torque pulsation or mass imbalance. S3. The harmonics corresponding to the vibration conditions classified as electromagnetic torque pulsation are input into the proportional resonant controller. The proportional resonant controller generates a reverse compensation current and inputs it into stator 1 to cancel the torque pulsation at that frequency. S4. Input the harmonics corresponding to the vibration conditions classified as mass imbalance into the suppression model, output the corresponding electromagnetic force compensation current and input it into stator 1 to counteract the unbalanced force.

[0081] Vibration state observers provide "eyes" to sense minute vibrations that cannot be directly measured in real time.

[0082] By separating the vibration source and using a proportional resonant controller (to suppress electromagnetic harmonics) and a suppression model (to suppress mechanical unbalanced forces) for targeted compensation, a leap from "passive vibration reduction" to "active vibration suppression" has been achieved.

[0083] Specifically, the vibration state observer, proportional resonant controller, and suppression model are all parts of the controller.

[0084] For the separate vibration source in S1, based on the relationship between frequency and rotational speed, specifically, the excitation source of mechanical vibration is the physical imbalance of the rotor, which has a relatively low frequency, usually an integer multiple of the rotational speed. The formula is as follows: ; ; Rotor rotation frequency (Hz); Mechanical rotation frequency (Hz); Rotational speed (rpm); The excitation source of electromagnetic vibration is the force wave of magnetic field interaction, which has a high frequency and is strongly correlated with electrical frequency.

[0085] ; ; : Electrical frequency (Hz), i.e., the fundamental frequency of the stator current; n: Number of pole pairs of the motor; Rotor frequency (Hz); Poles: Total number of poles in the motor; First, the vibration state observer estimates the actual torque ripple. and radial force This is the cleanest signal source.

[0086] Use a high-pass filter to remove extremely low-frequency drift and a low-pass filter to remove irrelevant high-frequency noise.

[0087] Remove the linear or slow-changing trend of the signal, making the data more stable and facilitating spectrum analysis.

[0088] The preprocessed time-domain vibration signal (amplitude varies with time) is converted into a frequency-domain spectrum (amplitude varies with frequency), and a spectrum diagram is constructed.

[0089] The vibration state observer calculates the characteristic frequency at the current rotational speed and matches it with the peak value in the spectrum.

[0090] (1st order, most common, caused by mass imbalance) (Second order, possibly caused by misalignment or bending) ; Calculate the characteristic frequency of electromagnetic vibration: = Z× (The tooth frequency, which is the product of the number of stator slots Z and the rotational frequency, is the main frequency of the cogging torque.) (6th harmonic, the most common, generated by the combined effect of inverter power supply and magnetic field harmonics) (12x frequency) ; In the spectrum, look for... , ...peaks appearing near the frequency. These peaks are classified as mechanical vibrations.

[0091] Searching in , ...peaks appearing near the frequency. These peaks are classified as electromagnetic vibrations.

[0092] Set an amplitude threshold for each characteristic frequency that needs attention.

[0093] Only when the amplitude of a certain frequency component exceeds its threshold is the vibration component considered to be significantly present and needs to be suppressed.

[0094] Establish a list of significant mechanical vibration frequencies and a list of significant electromagnetic vibration frequencies. This list will directly guide the subsequent controller for targeted suppression.

[0095] Among them, the vibration state observer is mainly used to estimate the vibration state that cannot be directly measured in real time when there are no physical sensors.

[0096] Its mathematical model is: Direct-axis / quadrature-axis current; ω, θ: Rotor speed and position; : Torque pulsation to be estimated; Radial vibration forces in the X and Y directions to be estimated.

[0097] This is performed using an extended Kalman filter (EKF); specifically, it includes the following steps: Prediction steps: Based on the state estimate from the previous time step and the current control input (V) d V q The current state and system output are predicted using a motor model (an existing model).

[0098] Update steps: Convert the actual system output (measured current) to... The predicted output is compared with the Kalman gain, and the predicted value is corrected to obtain the optimal state estimate.

[0099] Input: Control voltage V d V q ;Measured values: phase currents Ia, Ib, Ic (converted to Id, Iq).

[0100] Output: Estimated vibration state .

[0101] The extended Kalman filter is an existing device.

[0102] Its working process is as follows: Controller output V d V q It is given to the inverter and also to EKF.

[0103] EKF uses a motor model to predict the current... and vibration state.

[0104] Current sensor measures the real .

[0105] EKF calculates the prediction error: e = [ - , - ]^T.

[0106] EKF updates its state estimate based on the Kalman gain to obtain the optimal result. This process is recursively performed in each control cycle (on the order of microseconds).

[0107] A proportional resonant controller primarily generates a perfectly compensated signal at a specific frequency to eliminate vibrations at that frequency. Proportional resonant controllers are commercially available.

[0108] The proportional resonant controller consists of an ideal PR controller transfer function and a frequency adaptive module.

[0109] The PR controller transfer function is: G pr(s) = Kp + (2×K r ×ω c ×s) / (s 2 +2×ω c ×s+ω0 2 ); Kp: Proportional gain, providing wideband control.

[0110] Kr: Resonant gain, which determines the magnitude of the gain at the resonant frequency.

[0111] ω0: Resonant center frequency (rad / s). This is the core of the PR controller, which locks onto this frequency.

[0112] ω c The cutoff frequency determines the width (bandwidth) of the resonant peak. ω c The larger the value, the better the controller adapts to frequency changes, but the resonant gain decreases slightly.

[0113] For motor control, ω0 is not a fixed value, but rather depends on the motor's electrical frequency ω. e Related, for example, ω0 = 6 × ω e The frequency adaptive module can update the value of ω0 in real time.

[0114] The working process of the proportional resonant controller is as follows: Torque pulsation estimates received from the vibration state observer .

[0115] right Perform FFT analysis to determine the main vibrational frequency components (e.g., 6f). e ).

[0116] Therefore, the center frequency ω0 of the proportional resonant controller is set to 2. π 6 f e .

[0117] PR controller will This serves as the error signal e(t).

[0118] In e(t), only the component with frequency ω0 is greatly amplified by the PR controller (theoretically, the gain is infinite).

[0119] The proportional resonant controller outputs a sinusoidal compensation signal ΔIq′ with the same frequency as the ω0 component in e(t) but with opposite phase.

[0120] ΔIq′ is injected into the current loop, generating a counteracting torque that perfectly cancels out 6f. e Torque pulsation.

[0121] The suppression model consists of: a force mapping matrix, an inverse model solver, and a control law.

[0122] The force mapping matrix is ​​a mathematical model used to describe how an electric current generates a radial force. It is a 2x2 matrix G: [Fx, Fy] T = G [Id, Iq] T This matrix G can be obtained through offline calculation using finite element analysis, or through online system identification technology.

[0123] To generate a specific force, the inverse (or pseudo-inverse) of the force mapping matrix needs to be found: [ΔId′, ΔIq′]. T = G -1 [F desx , F desy ] T ; The force to be generated [F] desx , F desy ] T To counteract vibration, [Fdesx, Fdesy] can be used. T = -[F radxhat , F radyhat ] T That is, (expected force = negative estimated vibration force).

[0124] Its working process is as follows: Radial vibration force estimates received from the observer .

[0125] The control law calculates the desired compensation force to be generated: [F] desx , F desy ] T = -[F radxhat , F radyhat ] T .

[0126] The inverse model solver utilizes the inverse G of the force mapping matrix. -1 Calculate the compensation current [ΔId′, ΔIq′] required to generate the desired compensation force. T .

[0127] The compensation currents ΔId′ and ΔIq′ are fed forward into the current command of the controller; Id′′ total = Id′ +ΔId′;Iq′′ total = Iq′ + ΔIq′; The motor executes a new current command, generating a precise electromagnetic force that directly counteracts the mechanical vibration force, thereby suppressing vibration.

[0128] Specifically, the mathematical model of current and radial force [Fx, Fy]T = G [Id, Iq]T can be replaced with a lightweight neural network (such as a small deep neural network or an RBF network), whose function is: F field = G nn (Id, Iq, θ, Sat Level , Temp).

[0129] Among them, Sat Level (Saturation level): A parameter characterizing the degree of magnetic saturation of the iron core, calculated from Id and Iq.

[0130] The force field output is the "current" electromagnetic force field, calculated in real time based on the current currents Id and Iq.

[0131] Take the negative value F of the vibrational force field directly. supdes = -F vibhat As an "expected" suppressive force field. The "expected" suppressive force field is a vector target. F supdes For expected compensating force; F vibhat It is a vibrational force.

[0132] When the requirement is to solve for an optimal set of current commands Iopt dq′ This makes the "predicted electromagnetic field" generated by the current as close as possible to the "desired suppression field".

[0133] Use the function: min || F supdes - G nn (I d , I q , θ,S atLevel , Temp) ‖ (Minimize the L2 norm, i.e., the difference in force fields); The constraints are as follows: I dmin ≤ I d ≤ I dmax ; I qmin ≤ I q ≤ I qmax ; Id 2 + I q 2 ≤ I max 2 (Current limiting circle); (ωxL q xI q ) 2 + (ωxL d xI d + ωxΨ pm ) 2 ≤ V max 2 (Voltage limit ellipse); Where ω: electric angular velocity of the motor; L d ,L q : dq axis inductance; I d ,I q dq axis current; Ψ pm : Permanent magnet flux linkage; V max Maximum output voltage amplitude of the inverter; In each control cycle, numerical optimization algorithms (existing algorithms) such as gradient descent or interior point method are used to quickly solve this optimization problem and obtain the optimal solution I. optdq′ = [Id′, Iq′] T .

[0134] The suppression model also features an online self-learning engine, primarily ensuring that matrix G... nn Always accurate.

[0135] Its working principle is as follows: When the control system has a margin (such as in steady-state operation), under normal current command I... dq′ A weak, high-frequency orthogonal detection signal [ΔI] is superimposed on top. dprobe , ΔI qprobe ].

[0136] The minute electromagnetic force change ΔF caused by this probe signal was measured using EKF. measure .

[0137] (ΔI) dprobe , ΔI qprobe , ΔF measure As a data sample, for neural network G nn Perform online incremental learning (e.g., using recursive least squares to update network weights) to keep the model's predictions consistent with the actual measurements.

[0138] A complete data sample is: (input state, input perturbation, output perturbation), that is: Snew = (X, ΔI dqprobe , ΔF meas ); ΔI dqprobe Orthogonal detection signal [ΔI] dprobe , ΔI qprobe ]; Detection signal ΔI dqprobe The resulting change in electromagnetic force is ΔF meas ; Where X = [θ, Id, Iq, Temp, ...] is the complete state of the motor at the detection moment.

[0139] New sample S new Store it in a fixed-size circular queue (experience replay pool).

[0140] This experience replay pool always retains the latest N data samples. Old data is overwritten by new data, ensuring that the learner always learns from the most recent operating region.

[0141] Training a neural network directly with new data will overwrite previously learned weights, leading to "catastrophic forgetting." Therefore, the following algorithm is used to calculate the importance Ω of the weights: After training the network at a stable operation point A, calculate all network weights w. i The Fisher Information Matrix. i The larger the value w, the greater the weight. i The greater the importance of task A.

[0142] Ω i = F i (The importance of weight w_i); When using new data S new When training the network, the loss function is no longer a simple prediction error, but instead includes a regularization penalty term: For example: L total = L prediction + λ L ewc L prediction Predictive loss (such as mean squared error, MSE) measures how well new data fits.

[0143] L ewc The penalty term is calculated using the formula: Σ i [Ω i (w i - w iA ) 2 ]; w iA : These are the weight values ​​that the network has trained on task A.

[0144] L ewc The physical meaning: It punishes those tasks that are important to the old ones (Ω). i (large) and current value (w) i Trying to move away from already learned values ​​(w) iA The weights of ) are λ, which is a hyperparameter that balances the learning intensity of new and old tasks.

[0145] The algorithm freely adjusts the less important weights to fit new data, but at the same time it "flexibly" holds back the important weights to prevent them from changing drastically, thus protecting old knowledge.

[0146] The prior optimizations to this algorithm are as follows: This algorithm can continuously monitor the system's operating status.

[0147] Upon reaching steady state, a "probe-measure" process is triggered to acquire a new sample S. new And store it in the experience pool.

[0148] A small batch of samples is randomly drawn from the experience pool.

[0149] Perform one optimization step, using the L_total loss function described above, and apply the stochastic gradient descent algorithm to G. nn The weights are updated slightly.

[0150] This process is ongoing online, and the network weights are constantly and slowly evolving, increasingly and accurately approximating the actual, time-varying dynamic characteristics of the motor.

[0151] This method is called Elastic Weight Consolidation (EWC).

[0152] Through this combined strategy of active detection, experience replay, and EWC incremental learning, we endow the neural network G with... nn The ability to "learn for life." It is no longer a fixed model after offline training, but a living, adaptive brain capable of: compensating for aging and temperature drift; adapting to nonlinearity at different operating points; and continuously self-optimizing and self-calibrating without stopping the system.

[0153] The above are merely optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A motor rotor for mounting within the stator of a motor, characterized in that, include: The iron core is a plurality of iron cores stacked together in sequence; a mounting hole is provided at the center of each iron core, and a rotating shaft is inserted and fixed in the mounting hole; each iron core has a plurality of magnetic grooves; the plurality of magnetic grooves are distributed around the mounting hole in a circumferential direction. The permanent magnets are arranged in a one-to-one correspondence with the number of magnetic slots; the permanent magnets are engaged in the magnetic slots; the outer circle of the iron core corresponding to the area between two adjacent magnetic slots is planar.

2. The motor rotor according to claim 1, characterized in that, The iron core has multiple cooling channels; the middle of the rotating shaft has a main channel for coolant to flow in; the cooling channels are connected to the main channel through a first connecting channel; the cooling channels are connected to the magnetic groove through a second connecting channel; both ends of the magnetic groove have openings that communicate with the outer circle of the iron core.

3. The motor rotor according to claim 2, characterized in that, One end of the rotating shaft is rotatably connected to an oil supply connector, and the rotating shaft and the oil supply connector are sealed together; the oil supply connector is connected to the main channel; the oil supply connector is used to connect with external cooling oil.

4. The motor rotor according to claim 3, characterized in that, A reflux groove is provided on the lower part of the inner wall of the stator.

5. The motor rotor according to claim 4, characterized in that, The inner wall of the stator has multiple racks for winding electromagnetic coils; the multiple racks are distributed circumferentially along the inner wall of the stator; two adjacent racks are directly fixedly connected to a sealing strip.

6. The motor rotor according to claim 5, characterized in that, The stator has multiple cooling circuits; each cooling circuit includes a water outlet passage and a return passage; each return passage passes through one of the multiple racks respectively.

7. The motor rotor according to claim 5, characterized in that, The sealing strip is made of magnetic material.

8. The motor rotor according to any one of claims 1-7, characterized in that, The magnetic groove is V-shaped, and two permanent magnets are arranged at intervals in each magnetic groove.

9. The motor rotor according to claim 8, characterized in that, A vibration state observer for detecting the vibration of the shaft is fixedly installed on the stator; the vibration state observer is electrically connected to the controller; the stator is electrically connected to the controller.

10. A rotor vibration control method for controlling the motor rotor as described in claim 9, characterized in that, Includes the following steps: Identify the vibration source based on the vibration signal from the vibration state observer; The harmonic frequencies of the vibration source are classified into vibration conditions of electromagnetic torque pulsation or vibration conditions of mass imbalance. The harmonics corresponding to the vibration conditions of the electromagnetic torque pulsation are input into the proportional resonant controller, which generates a reverse compensation current and inputs it into the stator to cancel the torque pulsation at that frequency. The harmonics classified as corresponding to the vibration conditions of mass imbalance are input into the suppression model, and the corresponding electromagnetic force compensation current is output and input into the stator to counteract the unbalanced force.

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