Permanent magnet synchronous motor vibration suppression control method based on direct-axis current field weakening

Abstract

The application provides a vibration suppression control method of a permanent magnet synchronous motor based on a direct-axis current field weakening effect, in which a negative direct-axis current amplitude is increased as much as possible within a rated current range, and a magnetic field generated by the negative direct-axis current weakens a rotor permanent magnet field and an air gap field. According to a formula obtained by calculating a radial electromagnetic force density by using a Maxwell tensor method, a permanent magnet fundamental wave magnetic field and an armature fundamental wave magnetic field directly affect a two-fold frequency radial electromagnetic force, and the two are main sources of the radial electromagnetic force. In the application, the direct-axis magnetic field is weakened, the two-fold frequency radial electromagnetic force is reduced, and then the motor vibration is suppressed under the condition that the performance of the motor is ensured and the output torque remains unchanged.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, and in particular relates to a vibration suppression control method for permanent magnet synchronous motors based on the magnetic weakening effect of direct-axis current, applicable to permanent magnet synchronous motors. Background Technology

[0002] With rapid economic development, noise pollution has become an increasingly important issue. Prolonged work and life in noisy environments can cause a series of physiological and pathological changes in the human nervous, cardiovascular, and endocrine systems. Meanwhile, as an important tool widely used in social production and daily life, reducing the vibration and noise of electric motors has become a major focus. Especially in specific applications such as electric vehicles, medical devices, household appliances, and high-precision CNC machine tools, the vibration and noise levels of motors are crucial indicators of motor performance. Therefore, suppressing motor vibration and noise is of significant practical importance for improving motor performance and expanding the application range of permanent magnet motors.

[0003] There are three sources of vibration and noise in electric motors: mechanical vibration, air vibration, and electromagnetic vibration. With improvements in design and manufacturing processes, the noise generated by mechanical and air vibrations has been effectively reduced. Therefore, the main source of vibration and noise in electric motors is currently electromagnetic vibration. Electromagnetic vibration is excited by the electromagnetic excitation force generated by the air gap magnetic field acting on the iron core, and is primarily excited by radial electromagnetic force.

[0004] Traditional vector control of permanent magnet synchronous motors mainly considers performance aspects such as electromagnetic torque, torque ripple, and motor losses. However, current methods for suppressing electromagnetic vibration in motors often have a significant impact on these performance aspects.

[0005] Therefore, there is an urgent need for a method to suppress motor vibration control in situations where the requirements for motor vibration and noise are stringent, without affecting the normal operation of the motor. Summary of the Invention

[0006] Purpose of the invention: This invention provides a vibration suppression control method for permanent magnet synchronous motors based on the magnetic weakening effect of direct-axis current. Its purpose is to solve the problem that previous methods for suppressing electromagnetic vibration of motors have a significant impact on motor performance.

[0007] Technical solution: A vibration suppression control method for permanent magnet synchronous motors based on the field weakening effect of direct-axis current, specifically including: Step 1: Under normal operating conditions, determine the required direct-axis armature current of the motor. i dm and cross-axis armature current i qm ; Step 2: Use the direct-axis armature current obtained in Step 1 i dm and cross-axis armature current i qm Based on the principles of suppressing vibration current trajectory and not affecting the motor output electromagnetic torque, the compensation current Δ of the direct-axis current at the current moment is calculated. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k); Step 3: Calculate the compensation current Δ of the direct-axis current obtained in Step 2 at the current moment. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k) Inject into the motor control system to suppress electromagnetic vibration of the motor; The required direct-axis armature current and quadrature-axis armature current of the motor are obtained in step 1 based on the maximum torque-current ratio control algorithm or based on... i d =0 control algorithm; the method for obtaining the required direct-axis armature current and quadrature-axis armature current of the motor using the maximum torque-current ratio control algorithm is as follows:

[0008] In the formula: i sm The current vector magnitude under the maximum torque-to-current ratio algorithm is obtained from the speed loop output. ψ f , L d , L q These are permanent magnet flux linkage, direct-axis inductance, and quadrature-axis inductance, respectively. The principle of not affecting the motor output electromagnetic torque mentioned in step 2 is: it is necessary to ensure that the electromagnetic torque Δ generated by the compensation current is not affected. T e It equals 0, which means it satisfies:

[0009] In the formula, T em This refers to the original electromagnetic torque of the motor. p n The number of magnetic pole pairs; The principle of suppressing the vibration current trajectory described in step 2 is achieved by inputting compensation currents for both the direct-axis and quadrature-axis currents to increase the amplitude of the negative direct-axis current within the rated current range. This ensures that the motor always operates on the vibration-suppressing current trajectory, meaning the motor current satisfies the following:

[0010] In the formula, i smax This represents the maximum current capacity of the motor control system. i dr To suppress the actual direct-axis current under the vibration current trajectory; i qr To suppress the actual cross-axis current under the vibration current trajectory; In step 2, calculate the compensation current Δ of the direct-axis current at the current moment. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k) The method is as follows:

[0011] In the formula, i qr The actual value of (k) is equal to the sum of the maximum torque current ratio, the algorithm current, and the compensation current at the previous moment, i.e.: i qr (k)= i qm (k-1) +Δ i q (k-1); The compensation currents for the direct-axis current and the quadrature-axis current should also satisfy the following relationship:

[0012] In the formula: Δ i s The magnitude of the injected compensation current.

[0013] Furthermore, after injecting the compensation current into the motor system, the actual direct-axis current and quadrature-axis current of the motor are the sum of the direct-axis current calculated by the maximum torque current ratio control algorithm and the compensation current of the current direct-axis current, and the sum of the quadrature-axis current calculated by the maximum torque current ratio control algorithm and the compensation current of the current quadrature-axis current, respectively, which satisfies:

[0014] This is to suppress electromagnetic vibration of the motor.

[0015] A vibration suppression control system for a permanent magnet synchronous motor includes an armature current acquisition module, a compensation current acquisition module, and an output module. The armature current acquisition module, under normal operating conditions, determines the required direct-axis armature current i of the motor. dm and cross-axis armature current i qmAnd input to the compensation current acquisition module; the compensation current acquisition module uses the direct-axis armature current i input from the armature current acquisition module. dm and cross-axis armature current i qm Based on the principles of vibration suppression current trajectory and not affecting the motor output electromagnetic torque, the compensation current Δi of the direct-axis current at the current moment is calculated. d (k) and the compensation current Δi of the quadrature-axis current at the current moment q (k) is input to the output module; the output module will obtain the compensation current Δi of the direct-axis current at the current moment from the compensation current acquisition module input. d (k) and the compensation current Δi of the quadrature-axis current at the current moment q (k) Inject into the motor control system to suppress electromagnetic vibration of the motor.

[0016] Advantages and effects: This invention provides a vibration suppression control method for permanent magnet synchronous motors based on the magnetic weakening effect of direct-axis current. Within the rated current range, the amplitude of the negative direct-axis current is maximized. The magnetic field generated by the negative direct-axis current weakens the magnetic field of the rotor permanent magnet and the air gap magnetic field. As shown in the formula derived from the Maxwell tensor method for calculating radial electromagnetic force density, the fundamental magnetic field of the permanent magnet and the fundamental magnetic field of the armature directly affect the second-harmonic radial electromagnetic force, both being the main sources of radial electromagnetic force. The fundamental magnetic field of the armature can be decomposed into a direct-axis magnetic field and a quadrature-axis magnetic field, where the direct-axis magnetic field is in phase with the fundamental magnetic field of the permanent magnet. Therefore, when the direct-axis magnetic field is constant, the electromagnetic force amplitude increases with the increase of the quadrature-axis magnetic field, and when the quadrature-axis magnetic field is constant, the electromagnetic force amplitude decreases with the decrease of the direct-axis magnetic field. Typically, the quadrature-axis current that generates the quadrature-axis magnetic field has a significant impact on the electromagnetic torque. To ensure motor performance and maintain a constant output torque, weakening the direct-axis magnetic field becomes the main way to reduce the second-harmonic radial electromagnetic force and thus suppress motor vibration. This invention utilizes the magnetic field generated by the input reverse direct-axis current to counteract the magnetic field of the rotor permanent magnet. By adjusting the direct-axis current, without changing the mechanical structure or adding external equipment, the second-harmonic radial electromagnetic force can be reduced while ensuring the electromagnetic torque output of the motor, thereby suppressing the electromagnetic vibration of the motor. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the fundamental magnetic field of a permanent magnet and the fundamental magnetic field generated by the fundamental current of the armature. Figure 2 This is the current trajectory diagram of the vibration suppression control algorithm; Figure 3 This is a block diagram of the vibration suppression control algorithm system; Figure 4 These are the speed waveforms of the vibration suppression control algorithm and the maximum torque-current ratio control algorithm; Figure 5The torque waveform diagrams are from the vibration suppression control algorithm and the maximum torque-current ratio control algorithm. Figure 6 This is a comparison chart of the amplitudes of the radial electromagnetic force of the motor at different orders between the vibration suppression control algorithm and the maximum torque-current ratio control algorithm. Figure 7 This is a comparison chart of motor vibration displacement amplitude under the vibration suppression control algorithm and the maximum torque-current ratio control algorithm. Detailed Implementation

[0018] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] This invention proposes a vibration suppression control method for permanent magnet synchronous motors based on the field weakening effect of direct-axis current. The method specifically includes the following steps: Step 1: Under normal operating conditions, determine the required direct-axis armature current of the motor. i dm and cross-axis armature current i qm The required direct-axis armature current and quadrature-axis armature current of the motor are derived based on the maximum torque-to-current ratio control algorithm or based on... i d =0 control algorithm; the method for obtaining the required direct-axis armature current and quadrature-axis armature current of the motor using the maximum torque-current ratio control algorithm is as follows:

[0020] In the formula: i sm The current vector magnitude under the maximum torque-to-current ratio algorithm is obtained from the speed loop output. ψ f , L d , L q These are permanent magnet flux linkage, direct-axis inductance, and quadrature-axis inductance, respectively. Step 2: Use the direct-axis armature current obtained in Step 1 i dm and cross-axis armature current i qm Based on the principles of suppressing vibration current trajectory and not affecting the motor output electromagnetic torque, the compensation current Δ of the direct-axis current at the current moment is calculated. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k); The principle of not affecting the motor output electromagnetic torque is: the electromagnetic torque Δ generated by the compensation current needs to be ensured. T e It equals 0, which means it satisfies:

[0021] In the formula, T em This refers to the original electromagnetic torque of the motor. p n The number of magnetic pole pairs; The principle of suppressing vibration current trajectory is to increase the amplitude of the negative direct-axis current within the rated current range by inputting compensating currents for both the direct-axis and quadrature-axis currents. This ensures that the motor always operates on the vibration-suppressing current trajectory, meaning the motor current satisfies:

[0022] In the formula, i smax This represents the maximum current capacity of the motor control system. i dr To suppress the actual direct-axis current under the vibration current trajectory; i qr To suppress the actual cross-axis current under the vibration current trajectory; Calculate the compensation current Δ of the direct-axis current at the current moment. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k) The method is as follows:

[0023] In the formula, i qr The actual value of (k) is equal to the sum of the maximum torque current ratio, the algorithm current, and the compensation current at the previous moment, i.e.: i qr (k)= i qm (k-1) +Δ i q (k-1); Step 3: Calculate the compensation current Δ of the direct-axis current obtained in Step 2 at the current moment. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k) Inject into the motor control system to suppress electromagnetic vibration of the motor.

[0024] The compensation currents for the direct-axis current and the quadrature-axis current should also satisfy the following relationship:

[0025] In the formula: Δ i sThe magnitude of the injected compensation current.

[0026] This method maximizes the amplitude of the negative direct-axis current within the rated current range, thereby weakening the rotor permanent magnet's magnetic field through the magnetic field generated by the negative direct-axis current. It also utilizes the magnetic field generated by the input reverse direct-axis current to cancel out the magnetic field of the rotor permanent magnet and the air gap magnetic field, and weakens the direct-axis magnetic field of the armature current. By adjusting the current, the second-harmonic radial electromagnetic force can be reduced while ensuring the motor's output torque, thus suppressing the motor's electromagnetic vibration.

[0027] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings, taking an 8-pole, 48-slot permanent magnet synchronous motor as an example. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0028] Example 1:

[0029] For ease of description, the direct axis will be referred to as the d-axis and the intersection axis as the q-axis.

[0030] To address the vibration problem of permanent magnet synchronous motors, and taking into account the vector control characteristics of permanent magnet synchronous motors, this invention provides a vibration suppression control method that does not affect the control performance of permanent magnet synchronous motors. This method involves maximizing the amplitude of the negative direct axis current within the rated current range, thereby weakening the amplitude of the air gap magnetic field and the radial electromagnetic force wave, thus reducing motor vibration.

[0031] Vibration reduction principle: The rotation of a permanent magnet synchronous motor is the result of the interaction between the magnetic field of the permanent magnet and the magnetic field of the armature. In addition to generating electromagnetic torque in the tangential direction, the magnetic field interaction also generates radial electromagnetic force, which is the main source of electromagnetic vibration.

[0032] When a motor operates under unsaturated conditions, the air gap magnetic field is usually considered as a superposition of the armature magnetic field and the permanent magnet magnetic field. Simultaneously, in rotor field-oriented control, the armature magnetic field can be approximated as a superposition of the d-axis and q-axis magnetic fields. (1) In the formula, This is the air gap magnetic field; The magnetic field of a permanent magnet; The armature magnetic field; The magnetic field generated by the direct-axis current; The magnetic field generated by the quadrature-axis current; Mechanical angle.

[0033] The expressions for each magnetic field in the formula are as follows: (2) In the formula, Permanent magnet Second harmonic magnetic field amplitude ; This represents the number of pole pairs of the motor. Electric angular velocity; , Permanent magnets Second harmonic magnetic field amplitude ; Indicates the direction of magnetic field rotation, when hour, ;when hour, .

[0034] The armature core of an electric motor is typically made of silicon steel sheets. Because the permeability of silicon steel is much greater than that of air, the tangential magnetic field in the air gap is extremely small compared to the radial magnetic field and can usually be ignored. Therefore, when calculating the radial electromagnetic force density using the Maxwell tensor method, it can be simplified to... (3) like Figure 1 As shown, when only the fundamental magnetic field of the permanent magnet is considered... and the fundamental magnetic field generated by armature current When, it can be written as (4) In the formula, the magnetic fields along the d and q axes , They are respectively (5) In the formula, This represents the amplitude of the fundamental magnetic field of the permanent magnet. The amplitude of the fundamental magnetic field generated by the direct-axis current; The amplitude of the fundamental magnetic field generated by the quadrature-axis current. This refers to the mechanical angular velocity of the motor.

[0035] Then there is (6) Based on this, the radial electromagnetic force can be derived as follows: (7) As shown in equation (7), the fundamental magnetic field of the permanent magnet and the fundamental magnetic field of the armature directly affect the second harmonic radial electromagnetic force. Furthermore, when the magnetic field... At a given time, the amplitude of the electromagnetic force varies with the quadrature-axis magnetic field. The cross-axis magnetic field increases with the increase of the magnetic field. At a given time, the amplitude of the electromagnetic force varies with the direct-axis magnetic field. The decrease is proportional to the decrease in magnitude. Typically, this generates a cross-axis magnetic field. quadrature axis current It has a significant impact on electromagnetic torque. Therefore, a reverse direct-axis magnetic field can be generated in the armature by injecting a reverse direct-axis current of the same magnitude. This is to suppress the electromagnetic vibration of the motor.

[0036] Furthermore, to meet the basic requirements of the motor control system, the current must provide the torque necessary for the motor to operate normally, that is, to satisfy... (8) In the formula, To output electromagnetic torque to the motor; The electromagnetic torque required by the system; The number of magnetic pole pairs; , These are direct-axis and quadrature-axis inductors, respectively. , These are the direct-axis and quadrature-axis currents, respectively. It is a permanent magnet flux linkage.

[0037] In the maximum torque-to-current ratio algorithm, the control objective is to generate maximum torque per unit current, and the current trajectory is as follows: Figure 2 The midpoint line abcde is shown. When a direct-axis current is needed to weaken the magnetic field and suppress vibration, as much magnetic-weakening direct-axis current as possible needs to be added while meeting the torque requirements, so that the current trajectory moves to the dashed line ABCDE.

[0038] This process is mainly constrained by two factors: firstly, the armature current amplitude is limited by the capacity of the motor and inverter; secondly, even when the motor operates under weak field conditions, it must still ensure sufficient electromagnetic torque output as required. In other words, 1. the current capacity of the motor control system cannot be exceeded during algorithm implementation; 2. the output electromagnetic torque remains constant during algorithm implementation. Figure 2 As shown, Figure 2 The midpoint line abcde represents the current trajectory of the maximum torque-to-current ratio control algorithm, and the dashed line ABCDE represents the vibration-suppressing current trajectory. The constant torque line... For example, under the maximum torque-to-current ratio control algorithm, the armature current operates at point d. To implement the vibration suppression control algorithm, its operating point needs to be moved to point D, thus suppressing electromagnetic vibration while satisfying the system's required electromagnetic torque. Therefore, a method of active suppression of electromagnetic vibration through current injection is proposed, i.e., the current vector originally operating at point d... ( Figure 2 Add a current vector to the base (represented by a dashed line at the midpoint) ( Figure 2(represented by a solid straight line), causing the current vector to change to ( Figure 2 (represented by a medium-thick dashed line), then we have satisfy (9) In the formula, there is And there are (10) In the formula, for The amplitude, i.e., the maximum current capacity of the motor control system; (k) represents the d-axis compensation current at the current moment; (k) represents the q-axis compensation current at the current moment.

[0039] And because (11) Substituting equation (11) into equation (10), we have (12) in, This is the maximum current capacity of the motor control system. The reference current amplitude obtained from the speed loop output; The current amplitude of the injected compensation current is the value at the current moment, and the variable to be determined is denoted as .

[0040] To maximize the direct-axis current amplitude without affecting the electromagnetic torque, current is injected based on the maximum torque-to-current ratio control, which leads to the following: (13) To compensate for the electromagnetic torque generated by the current.

[0041] in, , satisfy (14) In the formula, , , These are permanent magnet flux linkage, direct-axis inductance, and quadrature-axis inductance, respectively. To ensure that motor performance is not affected, the electromagnetic torque generated by the compensation current must be guaranteed. Then there is (15) By combining equations (14) and (15), we can obtain: (16) According to equation (16), we can obtain (17) (18) Substituting equations (14) to (17) into equation (18), we have (19) In the formula, there is (20) In the formula, This refers to the q-axis current collected by the current sensor. Ideally, the armature current of the motor at the current moment is equal to the current command output by the motor control algorithm at the previous moment. In actual control systems, it can be assumed that... It is approximately equal to the sum of the maximum torque current ratio, the algorithm current, and the compensation current. (twenty one) Substituting equation (20) into equations (17) and (19), we can obtain (twenty two) After injecting the compensation current into the motor system, the reference current under the vibration-suppressing current trajectory is the sum of the current calculated by the maximum torque-current ratio control algorithm and the compensation current, which satisfies: (twenty three) This is to suppress electromagnetic vibration of the motor.

[0042] In actual operation, the moment before the vibration suppression control method takes effect is time (k-1), at which time Δi d (k-1), Δi q (k-1) is zero, and the motor current is idm and iqm obtained from the maximum torque-current ratio control algorithm; at time k, the current armature current signal iqr(k) is read through the current sensor, and at this time i qr (k)=i qm +Δi q (k-1), and use this to calculate the compensation current of the d-axis and q-axis currents at time k, i.e., the compensation current Δi. d (k), Compensation current Δi q (k).

[0043] The calculation at time k will then be repeated continuously to ensure stable motor operation under the vibration suppression control algorithm. For example, at time k+1, the current armature current signal iqr(k+1) is read by the current sensor, at which time i qr (k+1)=i qm +Δi q (k), and use this to calculate the compensation current of the d-axis and q-axis currents at time k, i.e., the compensation current Δi. d (k+1), compensation current Δi q(k+1).

[0044] The motor control system is constructed based on equations (22) to (23), and the control system block diagram is as follows. Figure 3 As shown.

[0045] The motor control system was simulated using MATLAB / Simulink. The motor started with an initial load of 0.5 Nm, and the load was increased to 5 Nm at 1 second. The motor speed and electromagnetic torque were as follows: Figure 4 , Figure 5 As shown. Figure 4 , Figure 5 In the diagram, the dashed line represents the motor speed or electromagnetic torque under the traditional maximum torque-current ratio control algorithm, while the solid line represents the motor speed or electromagnetic torque under the vibration suppression control method for permanent magnet synchronous motors based on the direct-axis current field weakening effect of the present invention. Some performance indicators of the vibration suppression control algorithm and the maximum torque-current ratio control algorithm are shown in Table 1.

[0046] Table 1 Ascent Time 0.189s 0.190s Overshoot 1.15% 1.21% Peak time 0.197s 0.199s Speed ​​change after load -6rpm -6.1rpm Speed ​​fluctuation 0.01% 0.01% Torque pulsation 2.15% 1.60% As can be seen from Table 1, the vibration suppression control method for permanent magnet synchronous motors based on the direct-axis current field weakening effect of the present invention has almost no impact on the control performance compared with the traditional maximum torque-current ratio control algorithm.

[0047] Finite element simulation was performed using COMSOL to obtain the radial electromagnetic force density and motor vibration displacement results as follows: Figure 6 , Figure 7 As shown. Figure 6 The white area represents the radial electromagnetic force amplitude of the traditional maximum torque-current ratio control algorithm, while the black area represents the radial electromagnetic force amplitude of the vibration suppression control method for permanent magnet synchronous motors based on the direct-axis current field weakening effect of the present invention.

[0048] The specific reduction in the amplitude of radial electromagnetic force density for each order is shown in Table 2. It can be seen that the higher-order electromagnetic force densities all decreased, especially the 8th-order electromagnetic force density amplitude, which has a greater impact on electromagnetic vibration, showed a significant reduction.

[0049] Table 2 0th order <![CDATA[125400N / m 2 ]]> <![CDATA[96799N / m 2 ]]> -22.81% 8th order <![CDATA[30022N / m 2 ]]> <![CDATA[13845N / m 2 ]]> -53.88% 16th order <![CDATA[28563N / m 2 ]]> <![CDATA[24939N / m 2 ]]> -12.69% 24th order <![CDATA[26041N / m 2 ]]> <![CDATA[24305N / m 2 ]]> -6.67% 32nd order <![CDATA[22154N / m 2 ]]> <![CDATA[20177N / m 2 ]]> -8.92% 40 levels <![CDATA[18641N / m 2 ]]> <![CDATA[10698N / m 2 ]]> -42.61% 48 steps <![CDATA[32415N / m 2 ]]> <![CDATA[22562N / m 2 ]]> -30.40% Displacement of any point on the outer side of the motor stator, such as Figure 7 As shown, Figure 7 The dashed line represents the radial displacement of a point on the housing in the traditional maximum torque-current ratio control algorithm, while the solid line represents the radial displacement of a point on the housing in the vibration suppression control method for permanent magnet synchronous motors based on direct-axis current field weakening of the present invention. Compared with the traditional maximum torque-current ratio control algorithm, the vibration suppression control method for permanent magnet synchronous motors based on direct-axis current field weakening of the present invention reduces the average displacement of a point on the stator housing surface by 10.15%.

[0050] This demonstrates that by altering the motor current trajectory and maximizing the amplitude of the negative direct-axis current within the rated current range, it is possible to maintain the control performance of the permanent magnet synchronous motor while simultaneously reducing the amplitude of the radial electromagnetic force wave and effectively suppressing the electromagnetic vibration of the motor.

[0051] Example 2: This invention also provides a vibration suppression control system for a permanent magnet synchronous motor based on the field weakening effect of direct-axis current, including an armature current acquisition module, a compensation current acquisition module, and an output module; the armature current acquisition module obtains the direct-axis armature current required by the motor under normal operating conditions. and cross-axis armature current The compensation current acquisition module receives the current from the armature current acquisition module; the compensation current acquisition module uses the direct-axis armature current input from the armature current acquisition module. and cross-axis armature current Based on the principles of suppressing vibration current trajectory and not affecting the motor output electromagnetic torque, the direct-axis compensation current is calculated. and cross-axis compensation current The current is input to the output module; the output module receives the direct-axis compensation current from the compensation current input to the module. and cross-axis compensation current Injected into the motor control system to suppress electromagnetic vibration of the motor.

[0052] 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 modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A vibration suppression control method for a permanent magnet synchronous motor based on the field weakening effect of direct-axis current, characterized in that: The method specifically includes: Step 1: Under normal operating conditions, determine the required direct-axis armature current of the motor. i dm and cross-axis armature current i qm ; Step 2: Use the direct-axis armature current obtained in Step 1 i dm and cross-axis armature current i qm Based on the principles of suppressing vibration current trajectory and not affecting the motor output electromagnetic torque, the compensation current Δ of the direct-axis current at the current moment is calculated. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k); Step 3: Calculate the compensation current Δ of the direct-axis current obtained in Step 2 at the current moment. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k) Inject into the motor control system to suppress electromagnetic vibration of the motor; The required direct-axis armature current and quadrature-axis armature current of the motor are obtained in step 1 based on the maximum torque-current ratio control algorithm or based on... i d =0 control algorithm; the method for obtaining the required direct-axis armature current and quadrature-axis armature current of the motor using the maximum torque-current ratio control algorithm is as follows: In the formula: i sm The current vector magnitude under the maximum torque-to-current ratio algorithm is obtained from the speed loop output. ψ f , L d , L q These are permanent magnet flux linkage, direct-axis inductance, and quadrature-axis inductance, respectively. The principle of not affecting the motor output electromagnetic torque mentioned in step 2 is: it is necessary to ensure that the electromagnetic torque Δ generated by the compensation current is not affected. T e It equals 0, which means it satisfies: In the formula, T em This refers to the original electromagnetic torque of the motor. p n The number of magnetic pole pairs; The principle of suppressing the vibration current trajectory described in step 2 is achieved by inputting compensation currents for both the direct-axis and quadrature-axis currents to increase the amplitude of the negative direct-axis current within the rated current range. This ensures that the motor always operates on the vibration-suppressing current trajectory, meaning the motor current satisfies the following: In the formula, i smax This represents the maximum current capacity of the motor control system. i dr To suppress the actual direct-axis current under the vibration current trajectory; i qr To suppress the actual cross-axis current under the vibration current trajectory; step 2 calculates the compensation current Δ of the current in the direct axis at the current moment. i d (k) and the compensation current Δ of the quadrature-axis current at the current moment i q (k) The method is as follows: In the formula, i qr The actual value of (k) is equal to the sum of the maximum torque current ratio, the algorithm current, and the compensation current at the previous moment, i.e.: i qr (k)= i qm (k-1) +Δ i q (k-1); The compensation currents for the direct-axis current and the quadrature-axis current should also satisfy the following relationship: In the formula: Δ i s The magnitude of the injected compensation current.

2. The vibration suppression control method for permanent magnet synchronous motors based on the field weakening effect of direct-axis current according to claim 1, characterized in that: After injecting the compensation current into the motor system, the actual direct-axis current and quadrature-axis current of the motor are the sum of the direct-axis current calculated by the maximum torque current ratio control algorithm and the compensation current of the current direct-axis current, and the sum of the quadrature-axis current calculated by the maximum torque current ratio control algorithm and the compensation current of the current quadrature-axis current, respectively, satisfying the following: This is to suppress electromagnetic vibration of the motor.

3. A vibration suppression control system for a permanent magnet synchronous motor, used to implement the vibration suppression control method for a permanent magnet synchronous motor based on the field weakening effect of direct-axis current as described in claim 1, characterized in that: It includes an armature current acquisition module, a compensation current acquisition module, and an output module; The armature current acquisition module determines the required direct-axis armature current i of the motor under normal operating conditions. dm and cross-axis armature current i qm And input the compensation current acquisition module; The compensation current acquisition module utilizes the direct-axis armature current i input from the armature current acquisition module. dm and cross-axis armature current i qm Based on the principles of vibration suppression current trajectory and not affecting the motor output electromagnetic torque, the compensation current Δi of the direct-axis current at the current moment is calculated. d (k) and the compensation current Δi of the quadrature-axis current at the current moment q (k), and input to the output module; The output module will obtain the compensation current Δi of the current direct-axis current at the current moment from the input of the compensation current acquisition module. d (k) and the compensation current Δi of the quadrature-axis current at the current moment q (k) Inject into the motor control system to suppress electromagnetic vibration of the motor.

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