Common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression method and system

Abstract

The invention discloses a sideband vibration suppression method and system for a common-mode voltage injection permanent magnet synchronous motor, and the method comprises the following steps: S1, calculating the injection range of a sideband common-mode voltage and the frequency component of the injected sideband harmonic voltage according to a sideband harmonic voltage model; s2, establishing a sideband vibration model under sideband common-mode voltage injection by combining the sideband electromagnetic force and the vibration transfer function; s3, taking the output of the sideband vibration model as a target function, taking minimization of a high-frequency vibration peak value of the motor as a target, and iteratively searching an optimal DC bias M0 and a third harmonic modulation ratio M3 based on a mode search algorithm; and S4, adjusting the distribution proportion of zero vectors SV0 and SV7 in space vector modulation SVPWM according to the optimal direct current bias M0 and the third harmonic modulation ratio M3 obtained by searching, and realizing common-mode voltage injection. According to the method, the common-mode voltage which has no influence on the fundamental frequency current is injected into the closed-winding permanent magnet synchronous motor, so that the high-frequency vibration of the motor caused by resonance is effectively inhibited.

Description

Technical Field

[0001] This invention relates to the field of motor vibration control, specifically to a method and system for suppressing sideband vibration of a common-mode voltage-injected permanent magnet synchronous motor. Background Technology

[0002] Currently, pulse width modulation (PWM) technology powered by frequency converters is widely used in the drive control of permanent magnet synchronous motors. However, while outputting the desired fundamental frequency, this modulation method inevitably generates sideband voltage harmonics near the switching frequency and its harmonics, thereby exciting sideband harmonic currents. Although the amplitude of these sideband harmonic currents is usually lower than that of low-frequency operating harmonics, the high-frequency electromagnetic forces they generate are highly susceptible to resonance with the motor's own structural modes (especially the 0th-order "breathing" mode), resulting in significant high-frequency vibration and noise. This problem not only affects the user experience but also shortens the motor's lifespan and severely restricts further performance improvements.

[0003] To suppress such vibrations, various solutions have been proposed in the industry. Compared to vibration suppression methods that require modifying the motor itself or using filters to remove vibration excitation sources, software strategies that optimize control algorithms to change the modulation frequency or method are widely favored because they do not increase hardware costs. However, these methods still have significant limitations: since motor drive systems need to adjust speed over a wide frequency range, vibration suppression methods that simply change the switching frequency have limited effective range and are not very effective; in addition, although spread spectrum modulation (such as random PWM) can reduce the resonance peak at a specific frequency by dispersing harmonic energy, the dispersed harmonic spectrum may also excite structural resonance in other frequency bands, and will also lead to increased switching losses, affecting system efficiency.

[0004] Therefore, while maintaining a fixed switching frequency, researching vibration suppression methods that can effectively avoid high-frequency resonance is of great practical significance for improving the noise performance and operational reliability of permanent magnet synchronous motors. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a common-mode voltage injection method for suppressing sideband vibration of a permanent magnet synchronous motor. This method effectively suppresses high-frequency vibration caused by resonance in the motor by injecting a common-mode voltage that has no effect on the base frequency current into the closed-winding permanent magnet synchronous motor.

[0006] The second objective of this invention is to provide a common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system, which effectively suppresses high-frequency vibrations caused by resonance in the motor by injecting a common-mode voltage that has no effect on the base frequency current into the closed-winding permanent magnet synchronous motor.

[0007] One of the objectives of this invention is achieved through the following technical solution: A common-mode voltage injection method for suppressing sideband vibration in permanent magnet synchronous motors, used to suppress high-frequency vibration of the motor caused by switching frequency sideband harmonics, includes the following steps: S1: Based on the sideband harmonic voltage model, calculate the injection range of the sideband common-mode voltage and the frequency components of the sideband harmonic voltage after injection.

[0008] Based on SVPWM, a DC bias M0 and a third common-mode harmonic M3 are injected, and the reference value of the injected common-mode voltage U during the switching cycle is... refc It can be written as: In the formula, M0 is the DC bias, and M3 is the third common-mode harmonic modulation ratio. ω is the fundamental angular frequency.

[0009] U refc The value range is determined by the adjustable range of the SV0 and SV7 allocation ratio in SVPWM. Let the sum of the duty cycles of the SV0 and SV7 vectors be D07, which can be calculated as: Then U refc The restricted range of values ​​is written as: Analysis of six-sector D 07 As can be seen from the expression, the effective vector duty cycle increases with the modulation ratio M, and the injected common-mode voltage U... refc The smaller the range of values.

[0010] Define the maximum limit value as M lim As shown in the following formula: The expression for the modulated wave after injection, f(t), is: In the formula, M is the modulation ratio.

[0011] By performing a double Fourier analysis on the above equation, the common-mode voltage injection condition is obtained. harmonic amplitude U of frequency mn for: In the formula, m is the sideband coefficient, n is the baseband coefficient, and V dc The median of the DC bus voltage is given by qmn = m + n / N, where N is the carrier ratio and J is the carrier frequency. k Let be the coefficients of the k-th order Bessel function, and The coefficients that vary with the sampling method are shown in the table below. Value table for variations in digital sampling method S2: Based on the sideband harmonic voltage frequency components, combined with the sideband electromagnetic force and vibration transfer function, a sideband vibration model under sideband common-mode voltage injection is established.

[0012] Establish a frequency domain model of the sideband electromagnetic force: In the above formula, L represents the inductance matrix.

[0013] Convert the three-phase voltage phasors and three-phase current phasors into rotating space vectors: In the formula It is a voltage rotation space vector. It is the space vector of the rotating current.

[0014] exist angular frequency Phase is The amplitude of the current is Imn, and the radial component Fr and tangential component Ft of the armature magnetomotive force of the sideband harmonic current it generates can be expressed as: In the formula, v is the spatial order of the armature magnetomotive force in the unit motor, and N t The number of unit motors is equal to the greatest common divisor of the number of pole pairs p and the number of slots z, θ is the mechanical rotation angle of the motor, and s n,v The direction of rotation of the armature magnetomotive force. This is the radial magnetomotive force amplitude coefficient. This is the amplitude coefficient of the tangential magnetomotive force.

[0015] For a permanent magnet, its magnetomotive force can be expressed as: in, φ0 = π / 2 + δ is the amplitude of the u-th order spatial harmonic magnetomotive force of the permanent magnet, u = 1, 3, 5, ..., φ0 = π / 2 + δ is the initial phase of the fundamental magnetomotive force of the permanent magnet, and δ is the torque angle of the motor.

[0016] Assuming the air gap permeability is Λ0, the radial component σ of the sideband electromagnetic force density is obtained using Maxwell's stress tensor method. r With tangential component σ t They are respectively: By equating the electromagnetic force density to the concentrated electromagnetic force on the stator tooth surface, the radial concentrated electromagnetic force F can be obtained. r Tangential concentrated electromagnetic force F t Ignoring the equivalent resultant torque M z : In the formula, L ef R is the effective length of the motor. si θ is the stator inner diameter, Δθ is the stator tooth surface width angle, and θ z This represents the position of the center line of the z-th stator tooth.

[0017] The tangential concentrated electromagnetic force in the stator teeth also induces radial vibration in the stator yoke, which can be equivalent to the radial concentrated electromagnetic force in the stator yoke. The equivalent F rt,z It can be represented as: In the formula p t h is the slot spacing. t For stator tooth height, w y The width of the stator yoke.

[0018] Total radial concentrated electromagnetic force F rsum It can be represented as F r With F rt,z sum: F rsum = F r F rt,z Let F rsum The v-th order electromagnetic force is F rsum,v ; definition The vibration transfer function of the v-th mode can be expressed as: In the formula, Φ v ω is the centroid-normalized mode shape vector of the v-th mode; v and ξ v These are the natural frequency and damping ratio of the v-th order, respectively; j represents the imaginary unit; ω represents the sideband vibration angular frequency, which is numerically related to the sideband voltage harmonic angular frequency ω. mn Same; T represents transpose operation.

[0019] The expression for the sideband vibration model used is as follows: In the formula, The amplitude of the sideband vibration is represented by v, and the order is represented by v. This represents the angular frequency of the sideband vibration, which is numerically related to the angular frequency of the sideband voltage harmonics. same.

[0020] S3: Using the output of the sideband vibration model as the objective function, with the goal of minimizing the peak value of the high-frequency vibration of the motor, the optimal DC bias M0 and the third harmonic modulation ratio M3 are iteratively searched based on the pattern search algorithm.

[0021] Initialize parameters such as the common-mode injection fundamental and third harmonic modulation ratios, step size, search grid expansion coefficient, and search grid contraction coefficient. Iteratively search the injected common-mode voltage components. By searching the DC bias and the third common-mode modulation ratios M0 and M3, minimize the peak high-frequency vibration Y of the motor. peak The purpose of (M0, M3) is to introduce parallel search, determine the globally optimal injected common-mode voltage component after the comparison process, and finally output the optimal injected common-mode voltage component to effectively suppress high-frequency vibration of the motor.

[0022] Based on the objective of suppressing sideband vibration, the goal is to minimize the peak value of the high-frequency vibration of the motor as Y. peak (M0, M3) is the target. The method proposed in this invention is based on a pattern search algorithm, which iterates according to the objective function. First, the common mode injection exploration value of the i-th (i=1,2,3,4) search interval is initialized. , And the updated value M 0_i M 3_i The parameters include step size ΔM0, ΔM3, search grid expansion coefficient γ (γ>1), and search grid contraction coefficient α (0<α<1). Then, the parameters during the iteration process... , The peak amplitude under each condition is compared with adjacent initial values ​​(intervals ΔM0 and ΔM3). After a successful move of step sizes ΔM0 and ΔM3, ΔM0 and ΔM3 are expanded to prevent the search from getting trapped in a local optimum; when a move fails and no possible optimal angle is found in the refined network, step sizes ΔM0 and ΔM3 are contracted. Then, M is iteratively updated by alternating between exploratory and pattern moves. 0_i M 3_i Exploring movement aims to acquire M 0_i M 3_i The optimization trend is observed, while mode shifting accelerates its convergence to the optimal electrical value. Finally, when the function tolerance... Less than ε or number of iterations Exceed When the time is reached, the iterative search process terminates and the optimal common-mode injection voltage component is output.

[0023] Furthermore, a parallel search process was designed to further reduce the possibility of convergence to a local optimum. The values ​​of M0 and M3 were divided into four parallel search regions, with 0 as the dividing line. Each of the four regions simultaneously and independently executed the iterative search process, outputting the optimal parameter combination within its region. Finally, the global optimum was selected from the optimal solutions of the four regions. Due to the constraints on the values ​​of M0 and M3, in each iteration, the probe point and its four surrounding points were first verified to ensure that M... lim If the defined constraint range exceeds the boundary, the parameter of that point will be forcibly corrected to the corresponding boundary value.

[0024] S4: Based on the optimal DC bias M0 and third harmonic modulation ratio M3 obtained from the search, adjust the allocation ratio of zero vector SV0 and SV7 in space vector modulation SVPWM to achieve common mode voltage injection.

[0025] Further, in step S1, the injected common-mode voltage reference value U refc Represented as: Where M0 is the DC bias and M3 is the third common-mode harmonic modulation ratio. U is the fundamental angular frequency. refc The value range is determined by the adjustable range of the allocation ratio of SV0 and SV7 in SVPWM.

[0026] Furthermore, the pattern search algorithm in step S3 is a two-dimensional pattern search algorithm, which includes an initialization step, a probing move step, and a pattern move step.

[0027] Furthermore, step S3 also includes a parallel search step: the values ​​of M0 and M3 are divided into four regions for parallel independent search, and finally the global optimal solution is selected from the optimal solutions of each region.

[0028] Furthermore, during the iterative search process, boundary constraints are checked on the values ​​of M0 and M3. If the values ​​exceed the maximum limit value M... lim The defined constraint range is then modified to the corresponding boundary values.

[0029] The second objective of this invention is achieved through the following technical solution: A common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system includes: The harmonic analysis module is used to calculate the injection range of the sideband common-mode voltage and the frequency components of the injected sideband harmonic voltage based on the sideband harmonic voltage model. The vibration modeling module is used to establish a sideband vibration model under sideband common-mode voltage injection based on the frequency components of the sideband harmonic voltage, combined with the sideband electromagnetic force and vibration transfer function. The optimization search module is used to take the output of the sideband vibration model as the objective function, with the goal of minimizing the high-frequency vibration peak of the motor, and iteratively search for the optimal DC bias M0 and third harmonic modulation ratio M3 based on the pattern search algorithm. The PWM modulation module is used to adjust the allocation ratio of zero vectors SV0 and SV7 in the space vector modulation (SVPWM) based on the optimal DC bias M0 and third harmonic modulation ratio M3 obtained by searching, so as to realize common-mode voltage injection.

[0030] Furthermore, the harmonic analysis module is configured to calculate the injected common-mode voltage reference value U. refc : Where M0 is the DC bias and M3 is the third common-mode harmonic modulation ratio. U is the fundamental angular frequency. refc The value range is determined by the adjustable range of the allocation ratio of SV0 and SV7 in SVPWM.

[0031] Furthermore, the optimized search module is configured to execute a two-dimensional pattern search algorithm, including an initialization logic unit, a probing movement logic unit, and a pattern movement logic unit.

[0032] Furthermore, the optimization search module also includes a parallel search logic unit, configured to divide the values ​​of M0 and M3 into four regions for parallel independent search, and finally select the global optimal solution from the optimal solutions of each region.

[0033] Furthermore, the optimization search module also includes a boundary constraint processing unit, configured to perform boundary constraint checks on the values ​​of M0 and M3 during the iterative search process. If the values ​​exceed the maximum limit value M... lim The defined constraint range is then modified to the corresponding boundary values.

[0034] Compared to existing technologies, the advantages of this invention are as follows: The common-mode voltage injection permanent magnet synchronous motor (PMSM) sideband vibration suppression method of this invention utilizes the independent adjustability of the common-mode injection parameters for each sector of the PMSM. Using DC bias M0 and the third harmonic M3 as joint optimization variables, it iteratively searches to minimize the amplitude of the high-frequency sideband electromagnetic force. This method requires no modification to the motor structure or additional hardware; it only needs to inject the calculated common-mode components into the SVPWM zero-vector allocation stage to reshape the inverter output harmonic spectrum, reduce the amplitude of the 0th-order radial force wave, and avoid structurally sensitive modes, thus achieving high-frequency vibration suppression. For different operating conditions, the algorithm can automatically converge to the optimal (M0, M3) combination, exhibiting good adaptability and ease of engineering use, providing an effective and low-cost solution for the quiet operation of high-power PMSMs at low switching frequencies. The common-mode voltage injection PMSM sideband vibration suppression system of this invention also possesses the above advantages. Attached Figure Description

[0035] Figure 1 This is a flowchart of the common-mode voltage injection method for suppressing sideband vibration of a permanent magnet synchronous motor in an embodiment of the present invention; Figure 2 This is a schematic diagram of the motor modulation stage for common-mode voltage injection in an embodiment of the present invention; Figure 3 This is a schematic diagram of the output harmonic spectrum after common-mode injection in an embodiment of the present invention; Figure 4 This is a schematic diagram of the common mode injection iterative search strategy flowchart in an embodiment of the present invention; Figure 5 This is a schematic diagram of the simulation iteration process at different speeds under rated operating conditions in an embodiment of the present invention; Figure 6 This is a block diagram of the common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system in an embodiment of the present invention; Figure 7 This is a block diagram of the optimized search module in an embodiment of the present invention. Detailed Implementation

[0036] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0037] Example 1 like Figure 1-5 As shown, this embodiment of the invention provides a method for suppressing sideband vibration of a permanent magnet synchronous motor via common-mode voltage injection, used to suppress high-frequency vibration of the motor caused by switching frequency sideband harmonics, including the following steps: S1: Based on the sideband harmonic voltage model, calculate the injection range of the sideband common-mode voltage and the frequency components of the sideband harmonic voltage after injection.

[0038] The injection of common-mode harmonic components can be achieved by dynamically adjusting Δt during the switching cycle. This involves injecting a DC bias M0 and the third common-mode harmonic M3, with the injection common-mode voltage reference value U during the switching cycle. refc It can be written as: In the formula, M0 is the DC bias, and M3 is the third common-mode harmonic modulation ratio. ω is the fundamental angular frequency.

[0039] Due to the introduction of Δt, the reference value of the injected common-mode voltage U during the switching cycle is... refc Already relative to V dc After normalization, Δt and U refc Values ​​are equal, such as Figure 2 As shown in the figure, T s The switching cycle.

[0040] U refc The value range is determined by the adjustable range of the allocation ratio of SV0 and SV7 in SVPWM. The duty cycle of the SV0 and SV7 vectors is D. sv0 and D sv7 The sum of the duty cycles of vectors SV0 and SV7 is D. 07 It can be calculated as: Then U refc The restricted range of values ​​is written as: Analysis of six-sector D 07 As can be seen from the expression, the effective vector duty cycle increases with the modulation ratio M, and the injected common-mode voltage U... refc The smaller the range of values, such as Figure 3 As shown.

[0041] Define the maximum limit value as M lim As shown in the following formula: The expression for the modulated wave after injection, f(t), is: In the formula, M is the modulation ratio.

[0042] By performing a double Fourier analysis on the above equation, the common-mode voltage injection condition is obtained. harmonic amplitude U of frequency mn for: In the formula, m is the sideband coefficient, n is the baseband coefficient, and V dc q is the median value of the DC bus voltage. mn =m+n / N, where N is the carrier ratio, J k Let be the coefficients of the k-th order Bessel function, and The coefficients vary with the sampling method.

[0043] S2: Based on the sideband harmonic voltage frequency components, combined with the sideband electromagnetic force and vibration transfer function, a sideband vibration model under sideband common-mode voltage injection is established.

[0044] By combining the sideband electromagnetic force and vibration transfer function, a sideband vibration model under sideband common-mode voltage injection is established. exist angular frequency Phase is The current amplitude is The radial component F of the armature magnetomotive force of the sideband harmonic current it generates r and tangential component F t It can be represented as: In the formula, v is the spatial order of the armature magnetomotive force in the unit motor, and N t The number of unit motors is equal to the greatest common divisor of the number of pole pairs p and the number of slots z, θ is the mechanical rotation angle of the motor, and s n,v The direction of rotation of the armature magnetomotive force. This is the radial magnetomotive force amplitude coefficient. This is the amplitude coefficient of the tangential magnetomotive force.

[0045] For a permanent magnet, its magnetomotive force can be expressed as: in, φ0 = π / 2 + δ is the amplitude of the u-th order spatial harmonic magnetomotive force of the permanent magnet, u = 1, 3, 5, ..., φ0 = π / 2 + δ is the initial phase of the fundamental magnetomotive force of the permanent magnet, and δ is the torque angle of the motor.

[0046] Assuming the air gap permeability is Λ0, the radial component σ of the sideband electromagnetic force density is obtained using Maxwell's stress tensor method. r With tangential component σ t They are respectively: By equating the electromagnetic force density to the concentrated electromagnetic force on the stator tooth surface, the radial concentrated electromagnetic force F can be obtained. r Tangential concentrated electromagnetic force F t Ignoring the equivalent resultant torque M z : In the formula, L ef R is the effective length of the motor. si θ is the stator inner diameter, Δθ is the stator tooth surface width angle, and θ z This represents the position of the center line of the z-th stator tooth.

[0047] The tangential concentrated electromagnetic force in the stator teeth also induces radial vibration in the stator yoke, which can be equivalent to the radial concentrated electromagnetic force in the stator yoke. The equivalent F rt,z It can be represented as: In the formula pt h is the slot spacing. t For stator tooth height, w y The width of the stator yoke.

[0048] Total radial concentrated electromagnetic force F rsum It can be represented as F r With F rt,z sum: F rsum = F r F rt,z Let F rsum The v-th order electromagnetic force is F rsum,v ; definition The vibration transfer function of the v-th mode can be expressed as: In the formula, Φ v ω is the centroid-normalized mode shape vector of the v-th mode; v and ξ v These are the natural frequency and damping ratio of the v-th order, respectively; j represents the imaginary unit; ω represents the sideband vibration angular frequency, which is numerically related to the sideband voltage harmonic angular frequency ω. mn Same; T represents transpose operation.

[0049] The expression for the sideband vibration model used is as follows: In the formula, The amplitude of the sideband vibration is represented by v, and the order is represented by v. This represents the angular frequency of the sideband vibration, which is numerically related to the angular frequency of the sideband voltage harmonics. same; In this embodiment, the introduction of DC bias M0 results in odd-order sideband harmonics near odd-order subcarriers and even-order sideband harmonics near even-order subcarriers. Based on the sideband voltage harmonic amplitude calculation results, it can be considered that after injecting the common-mode component, the sideband harmonics are mainly concentrated in f. s ±4f1 and 2f s Within the range of ±4f1. (f in the figure) s This refers to the switching frequency.

[0050] like Figure 3 As shown, with DC bias and the injection of the third common-mode harmonic, f s and 2f s The amplitudes of the major sideband harmonics in the vicinity change accordingly, and the variation patterns of the sideband harmonic amplitudes under M0 and M3 injections are inconsistent. Among them, DC bias injection affects f s ±f1、2f sThe ±f1 frequency output voltage harmonics have a significant impact, while the injection of the 3rd common-mode harmonic has a greater impact on f. s ±2f1、2f s ±2f1 and frequency output voltage harmonics have a significant impact.

[0051] S3: Using the output of the sideband vibration model as the objective function, with the goal of minimizing the peak value of the motor's high-frequency vibration, the optimal DC bias is iteratively searched based on a pattern search algorithm. And third harmonic modulation ratio .

[0052] Specifically, the steps include the following: (1) Initialization phase: Initialize the common modulus injection exploration value of the i-th (i=1,2,3,4) search interval. , and update value , Step length , Parameters such as the search grid expansion coefficient γ (γ>1) and the search grid contraction coefficient α (0<α<1).

[0053] (2) Exploratory movement: During each iteration, The high-frequency vibration peak at a given location is compared with the vibration peaks at eight surrounding locations. A detection movement is considered successful only if the high-frequency vibration peak at an adjacent detection point is lower than the minimum vibration peak value at the original detection point, and the result is updated. , These are the parameters for the successful detection point.

[0054] and The detection points are updated independently based on whether the peak value of the detection points in their respective directions is lower than the peak value of the original detection points. If the detection is successful, the detection step size in the corresponding direction is increased by the search grid expansion factor γ to search for possible optimal parameters over a larger range. Otherwise, the detection step size in the corresponding direction is decreased by the search grid contraction factor α to search for optimal parameters in a finer range.

[0055] If both sets of directional probing movements fail, the probing movement is considered to have failed. At this point, according to... and High-frequency vibration peak values ​​were compared and determined. and The updated value is obtained, and the step size in both directions is reduced simultaneously.

[0056] (3) Pattern shift: When the exploratory shift is successful, the pattern search will update the reference value according to the parameter difference direction of the adjacent successful detection points, and move the reference point to the new candidate area along the optimization trend.

[0057] (4) Parallel search: In order to further reduce the probability of convergence to a local optimum, the values ​​of M0 and M3 are divided into 4 parallel search regions with 0 as the dividing line. The 4 regions execute the iterative search process synchronously and independently, and each outputs the optimal parameter combination in its region. Finally, the global optimum is selected from the optimal solutions of the 4 regions.

[0058] Since the values ​​of M0 and M3 are constrained, in each iteration, the probe point and its four surrounding points are first verified to ensure that M is satisfied. lim If the defined constraint range exceeds the boundary, the parameter of that point will be forcibly corrected to the corresponding boundary value.

[0059] (5) Iteration termination determination: When the number of iterations reaches the limit value N. max The iteration ends when the change in the peak vibration value ρ is less than the allowable error ε in each successful iteration.

[0060] like Figure 3 As shown, after all intervals have completed the iteration, the global optimal M0 and M3 are determined by comparing the local optimal high-frequency vibration peak values ​​of each interval.

[0061] S4: Based on the optimal DC bias M0 and third harmonic modulation ratio M3 obtained from the search, adjust the allocation ratio of zero vector SV0 and SV7 in space vector modulation SVPWM to achieve common mode voltage injection.

[0062] Based on the injected common-mode voltages M0 and M3, the injection control of the common-mode component can be achieved by specifying the allocation ratio of the two sets of zero vectors SV0 (000) and SV7 (111) in the SVPWM strategy within each switching cycle.

[0063] In SVPWM, the duty cycles D of SV1 and SV2 are obtained from the vector decomposition relationship. sv1 and D sv2 for: Where M represents the inverter output modulation ratio, and its value ranges from 0 to 100 in the linear modulation interval. The duty cycle of the zero vector can be written according to SVPWM as: Therefore, the zero vector duty cycle in different sectors is determined by the duty cycles of the two effective vectors in the sector, and the three-phase modulation waveform and reference voltage of the fundamental period can be obtained from this.

[0064] Further, in step S1, the injected common-mode voltage reference value U refc Represented as: Where M0 is the DC bias and M3 is the third common-mode harmonic modulation ratio. U is the fundamental angular frequency. refc The value range is determined by the adjustable range of the allocation ratio of SV0 and SV7 in SVPWM.

[0065] Furthermore, the pattern search algorithm in step S3 is a two-dimensional pattern search algorithm, which includes an initialization step, a probing move step, and a pattern move step.

[0066] Furthermore, step S3 also includes a parallel search step: the values ​​of M0 and M3 are divided into four regions for parallel independent search, and finally the global optimal solution is selected from the optimal solutions of each region.

[0067] Furthermore, during the iterative search process, the values ​​of M0 and M3 are checked for boundary constraints. If they exceed the constraint range defined by the maximum limit value Mlim, they are corrected to the corresponding boundary values.

[0068] The common-mode voltage injection method for sideband vibration suppression of permanent magnet synchronous motors in this invention is based on a PWM output harmonic model. It accurately analyzes the high-frequency vibration response of the permanent magnet synchronous motor after common-mode voltage components are injected. By selectively injecting DC bias and third harmonic common-mode components into the modulation wave, the inverter output spectrum is adjusted, thereby weakening electromagnetic vibration in the resonant frequency band. With minimizing the high-frequency vibration peak value as the optimization objective, the optimal common-mode injection amount is iteratively searched using a two-dimensional pattern search algorithm based on the vibration calculation results under different common-mode voltage injection conditions. The common-mode voltage injection method for sideband vibration suppression of permanent magnet synchronous motors in this invention can quickly locate the optimal common-mode injection amount and achieve sideband vibration suppression optimization under complex operating conditions.

[0069] The main parameters of the motor used in this embodiment are shown in the table below: Main parameters table of motor The iterative process of the optimal common-mode injection parameters using the proposed two-dimensional pattern search strategy at different rotational speeds under rated operating conditions with a switching frequency of 5 kHz is as follows: Figure 5 As shown in the figure, the left side of the graph shows the change of high-frequency vibration peak values ​​with the number of iterations during the iteration process, with the peak values ​​marked by color bars. The bottom planar broken line shows the iteration changes of M0 and M3 in the four search intervals. The right side shows the iteration trajectories of the common modulus injection parameters M0 and M3 with the number of iterations. The initial settings for this example are: the initial values ​​of M0 and M3 in each interval are all set to (0,0), and the initial step size ΔM0 is the same as ΔM3, both being 0.05. α=0.5, γ=2, the maximum number of iterations is 20, and the allowable error is 0.01 g. The initial values ​​of M0 and M3 in the four search intervals are (M... lim / 4, M lim / 4), (M lim / 4,-M lim / 4), (-M lim / 4,-M lim / 4) and (M lim / 4,-M lim / 4).

[0070] When the switching frequency is 5kHz, taking 360 r / min and 720 r / min as examples, the high-frequency vibration peak value is reduced by 25.6% and 15.7% respectively compared with the high-frequency vibration peak value of 0.39 g and 0.51 g when no common-mode voltage is injected.

[0071] Example 2 like Figure 6-7 As shown, embodiments of the present invention also provide a common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system, including... The harmonic analysis module is used to calculate the injection range of the sideband common-mode voltage and the frequency components of the injected sideband harmonic voltage based on the sideband harmonic voltage model.

[0072] The vibration modeling module is used to establish a sideband vibration model under sideband common-mode voltage injection based on the frequency components of the sideband harmonic voltage, combined with the sideband electromagnetic force and vibration transfer function.

[0073] The optimization search module is used to take the output of the sideband vibration model as the objective function, with the goal of minimizing the high-frequency vibration peak value of the motor, and iteratively searches for the optimal DC bias M0 and third harmonic modulation ratio M3 based on the pattern search algorithm.

[0074] The PWM modulation module is used to adjust the allocation ratio of zero vectors SV0 and SV7 in the space vector modulation (SVPWM) based on the optimal DC bias M0 and third harmonic modulation ratio M3 obtained by searching, so as to realize common-mode voltage injection.

[0075] Furthermore, the harmonic analysis module is configured to calculate the injected common-mode voltage reference value U. refc : Where M0 is the DC bias and M3 is the third common-mode harmonic modulation ratio. U is the fundamental angular frequency. refc The value range is determined by the adjustable range of the allocation ratio of SV0 and SV7 in SVPWM.

[0076] Furthermore, the optimized search module is configured to execute a two-dimensional pattern search algorithm, including an initialization logic unit, a probing movement logic unit, and a pattern movement logic unit.

[0077] Furthermore, the optimization search module also includes a parallel search logic unit, configured to divide the values ​​of M0 and M3 into four regions for parallel independent search, and finally select the global optimal solution from the optimal solutions of each region.

[0078] Furthermore, the optimization search module also includes a boundary constraint processing unit, configured to perform boundary constraint checks on the values ​​of M0 and M3 during the iterative search process. If the values ​​exceed the maximum limit value M... lim The defined constraint range is then modified to the corresponding boundary values.

[0079] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for suppressing sideband vibration of a permanent magnet synchronous motor via common-mode voltage injection, used to suppress high-frequency vibration of the motor caused by switching frequency sideband harmonics, characterized in that, Includes the following steps: S1: Based on the sideband harmonic voltage model, calculate the injection range of the sideband common-mode voltage and the frequency components of the sideband harmonic voltage after injection; S2: Based on the frequency components of the sideband harmonic voltage, and combined with the sideband electromagnetic force and vibration transfer function, establish a sideband vibration model under sideband common-mode voltage injection; S3: Using the output of the sideband vibration model as the objective function, with the goal of minimizing the peak value of the high-frequency vibration of the motor, the optimal DC bias M0 and the third harmonic modulation ratio M3 are iteratively searched based on the pattern search algorithm. S4: Based on the optimal DC bias M0 and third harmonic modulation ratio M3 obtained from the search, adjust the allocation ratio of zero vector SV0 and SV7 in space vector modulation SVPWM to achieve common mode voltage injection.

2. The method for suppressing sideband vibration of a common-mode voltage-injected permanent magnet synchronous motor according to claim 1, characterized in that, In step S1, the injected common-mode voltage reference value U refc Represented as: Where M0 is the DC bias, M3 is the third common-mode harmonic modulation ratio, ω1 is the fundamental angular frequency, and U refc The value range is determined by the adjustable range of the allocation ratio of SV0 and SV7 in SVPWM.

3. The method for suppressing sideband vibration of a common-mode voltage-injected permanent magnet synchronous motor according to claim 1, characterized in that, The pattern search algorithm in step S3 is a two-dimensional pattern search algorithm, which includes an initialization step, a probing move step, and a pattern move step.

4. The method for suppressing sideband vibration of a common-mode voltage-injected permanent magnet synchronous motor according to claim 3, characterized in that, Step S3 also includes a parallel search step: the values ​​of M0 and M3 are divided into four regions for parallel independent search, and finally the global optimal solution is selected from the optimal solutions of each region.

5. The method for suppressing sideband vibration of a common-mode voltage-injected permanent magnet synchronous motor according to claim 3 or 4, characterized in that, During the iterative search, boundary constraints are checked on the values ​​of M0 and M3. If the values ​​exceed the maximum limit value M... lim The defined constraint range is then modified to the corresponding boundary values.

6. A common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system, characterized in that, include: The harmonic analysis module is used to calculate the injection range of the sideband common-mode voltage and the frequency components of the injected sideband harmonic voltage based on the sideband harmonic voltage model. The vibration modeling module is used to establish a sideband vibration model under sideband common-mode voltage injection based on the frequency components of the sideband harmonic voltage, combined with the sideband electromagnetic force and vibration transfer function. The optimization search module is used to take the output of the sideband vibration model as the objective function, with the goal of minimizing the high-frequency vibration peak of the motor, and iteratively search for the optimal DC bias M0 and third harmonic modulation ratio M3 based on the pattern search algorithm. The PWM modulation module is used to adjust the allocation ratio of zero vectors SV0 and SV7 in the space vector modulation (SVPWM) based on the optimal DC bias M0 and third harmonic modulation ratio M3 obtained by searching, so as to realize common-mode voltage injection.

7. The common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system according to claim 6, characterized in that, The harmonic analysis module is configured to calculate the injected common-mode voltage reference value U. refc : Where M0 is the DC bias, M3 is the third common-mode harmonic modulation ratio, ω1 is the fundamental angular frequency, and U refc The value range is determined by the adjustable range of the allocation ratio of SV0 and SV7 in SVPWM.

8. The common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system according to claim 6, characterized in that, The optimized search module is configured to execute a two-dimensional pattern search algorithm, including an initialization logic unit, a probing movement logic unit, and a pattern movement logic unit.

9. The common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system according to claim 8, characterized in that, The optimization search module also includes a parallel search logic unit, configured to divide the values ​​of M0 and M3 into four regions for parallel and independent search, and finally select the global optimal solution from the optimal solutions of each region.

10. The common-mode voltage injection permanent magnet synchronous motor sideband vibration suppression system according to claim 8 or 9, characterized in that, The optimization search module also includes a boundary constraint processing unit, configured to perform boundary constraint checks on the values ​​of M0 and M3 during the iterative search process. If the values ​​exceed the maximum limit value M... lim The defined constraint range is then modified to the corresponding boundary values.

Images