A test method of a motor rotor dynamic balance test system

Abstract

The application discloses a kind of rotor dynamic balance test system based on magnetic suspension bearing, including the drive motor of connecting the rotor to be measured, the inductive copper sleeve being arranged in the shaft extension end of the rotor to be measured and the two magnetic suspension bearings as rotor supporting unit, still including drive motor frequency converter, magnetic suspension bearing controller, rotational speed sensor and multiple eddy current displacement sensors;Its test method is also disclosed, drive magnetic suspension bearing controller controls the suspension and drop of magnetic suspension bearing, sends rotational frequency instruction to motor frequency converter to drive rotor rotation, the radial amplitude of rotor is collected and saved by data acquisition instrument in the process of rotor rotation, according to rigid rotor dynamic balance calculation model, the size and phase of correction mass are analyzed and calculated to vibration data.The application can directly complete the calculation of the dynamic balance precision of rotor by the industrial computer of control system, and the reverse suppression current applied to the rotor by the magnetic suspension bearing can reduce the vibration amplitude of the rotor, so that the rotor system is more stable.

Description

Technical Field

[0001] This invention belongs to the field of motor rotor dynamic balancing testing technology, and relates to a motor rotor dynamic balancing testing system based on magnetic levitation bearings, as well as its testing method. Background Technology

[0002] Uneven mass distribution in rotating machinery rotors causes them to be affected by unbalanced forces during rotation, thus reducing the lifespan of the rotating machinery. Therefore, dynamic balancing of the rotor is crucial.

[0003] The unbalanced force response of the drive motor rotor is proportional to the square of the rotational speed. Therefore, in order to prevent the unbalanced response from affecting the rotor during dynamic balancing tests, the remaining unbalance of the rotor is often tested at low speeds to calculate the dynamic balancing accuracy level of the rotor at high speeds. Summary of the Invention

[0004] To address the above shortcomings, one of the objectives of this invention is to propose a dynamic balancing test system for motor rotors based on magnetic levitation bearings.

[0005] The technical solution adopted by this invention patent to solve its technical problem is: a motor rotor dynamic balancing test system, including a drive motor connected to the rotor under test, an induction copper sleeve set at the shaft extension end of the rotor under test, and two magnetic levitation bearings as rotor support units, and also including a drive motor frequency converter and a magnetic levitation bearing controller respectively connected to the drive motor and the magnetic levitation bearings, as well as an eddy current displacement sensor and a speed sensor connected to an industrial control computer through a data acquisition instrument. The eddy current displacement sensor and the speed sensor are also connected to a data analyzer. The drive motor frequency converter and the magnetic levitation bearing controller are respectively connected to the industrial control computer through a 485 communication module.

[0006] The second objective of this invention is to propose a method for dynamic balancing of a motor rotor based on a magnetic levitation bearing, comprising the following steps:

[0007] Step 1: The industrial control computer drives the magnetic levitation bearing controller through the 485 communication module. After the magnetic levitation bearing is powered on, the force applied to the rotor under test makes the rotor under test float. Then, the air gap between the stator and rotor in the X and Y directions of the two magnetic levitation bearings is recorded. x a 、x b 、y a 、y b and current i xa 、i xb、 i ya 、i yb ;

[0008] Step 2: The industrial control computer sends a frequency conversion command to the drive motor inverter through the 485 communication module to drive the rotor under test to rotate.

[0009] Step 3: After the rotor under test has stabilized, the industrial control computer controls the data acquisition instrument to record and save the radial amplitude and speed of the rotor under test through two sets of four eddy current displacement sensors and one speed sensor, and send them to the data analyzer.

[0010] Step 4: First, establish the structural model of the rotor under test: based on the X-direction function f(i,x)=k of the electromagnetic force, current, and displacement of the magnetic levitation bearing. ix Ik x x and y direction functions f(i,y)=k iy Ik y y, where f(i,x) is the electromagnetic force on the magnetic levitation bearing in the X direction, f(i,y) is the electromagnetic force on the bearing in the Y direction, and k ix and k iy Let k be the current stiffness in the X and Y directions. x x and k y Let y be the displacement stiffness in the X and Y directions. This yields the force formulas that balance the weight and electromagnetic force acting on the rotor when it is statically suspended by the magnetic levitation bearing. Then, based on the actual structural model of the rotor being tested, input the distances g and h from the magnetic levitation bearings on both sides to the eddy current displacement sensor, as well as the distances i and j between the two magnetic levitation bearings at positions AB and the correction surface, and the radii r1 and r2 of the correction mass in the data analysis software of the data analyzer.

[0011] Step 5: The industrial control computer performs dynamic balance calculations based on the data saved by the data acquisition instrument and the radial amplitude and rotational speed collected by the data analysis instrument, according to the data read by the control data analysis software. The magnitude and phase of the correction mass are obtained, and the dynamic balance accuracy level of the rotor under test is calculated.

[0012] Furthermore, step 5 uses the following dynamic balancing calculation formula to calculate the dynamic balancing accuracy level:

[0013] A vector formed by the coordinates collected by the eddy current displacement sensor and the speed sensor. and the centroid coordinates of the rotor under test Combined force formulas and We can solve for a, b, c, d, e, and f:

[0014] ,

[0015] Where x seA y seALet x be the radial displacement of the displacement sensor at position A in the X and Y directions. seB y seB Let x be the radial displacement of the displacement sensor at position B in the X and Y directions. seA1 y seA1 Let x be the radial displacement of the rotor in the X and Y directions of the magnetic levitation bearing at point A. seB1 y seB1 Let B be the radial displacement of the rotor in the X and Y directions of the magnetic levitation bearing. The rotor coordinates are represented as x, y, ... and β, where β and β are the angles by which the rotor rotates counterclockwise around the x and y axes, respectively;

[0016] Let the force vector of the magnetic levitation bearing be... The force and torque of the bearing under the vector q can be expressed as: ,in The dynamic equation of the rotor considering the unbalance. Where U is the unbalanced centrifugal force matrix of the rotor. ,

[0017] In the formula, θ1 and θ2 are the angles between the correction mass and the X-axis on the two correction surfaces A and B, respectively, which are obtained after Laplace transform. After further conversion ,

[0018] Based on the rotor speed n and rotor radial amplitude x measured by the data acquisition instrument seA1 y seA1 x seB2 y seB2 The current i in the X and Y directions of the magnetic levitation bearing xa i xb i ya i yb and stator-rotor air gap x a x b y a y b The corrected masses m1 and m2 and the corrected phases θ1 and θ2 can then be solved, and the dynamic balancing accuracy level can be further calculated. .

[0019] The beneficial effects of this invention are as follows: The testing system of this invention can drive the magnetic levitation bearing controller to levitate and drop the magnetic levitation bearing, send frequency conversion commands to the motor inverter to drive the rotor to rotate. During rotor rotation, the data acquisition instrument collects and saves the radial vibration data of the rotor. Based on the dynamic balance calculation model of the rigid rotor, the data analyzer analyzes and calculates the magnitude and phase of the corrected mass based on the vibration data. During rotor rotation, the magnetic levitation bearing controller can identify the unbalanced force of the rotor and suppress the rotor vibration by applying a reverse force to the rotor. This invention can directly calculate the dynamic balance accuracy of the rotor through the industrial control computer of the control system. Applying a reverse suppression current to the rotor through the magnetic levitation bearing can reduce the vibration amplitude of the rotor, making the rotor system more stable. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the dynamic balancing test system of the present invention;

[0021] Figure 2 This is an operation flowchart of the dynamic balancing test system of the present invention;

[0022] Figure 3 This is a rotor parameter diagram of the radial magnetic levitation bearing model of the present invention;

[0023] Figure 4 This is a rotor structure diagram of the radial magnetic levitation bearing model of the present invention.

[0024] The labels for each figure are as follows: 1—Industrial control computer, 2—Data acquisition instrument, 3—485 communication module, 4—Eddy current displacement sensor, 5—Speed ​​sensor, 6—Data analyzer, 7—Drive motor frequency converter, 8—Magnetic levitation bearing controller, 9—Drive motor, 10—Magnetic levitation bearing. Detailed Implementation

[0025] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the embodiments described.

[0026] Reference Figure 1As shown, this invention discloses a motor rotor dynamic balancing test system, including a drive motor 9 connected to the rotor under test, an induction copper sleeve disposed at the shaft extension end of the rotor under test, and two magnetic levitation bearings 10 serving as rotor support units. The two magnetic levitation bearings 10 on the left and right sides have a certain air gap in contact with the rotor under test. When the magnetic levitation bearings 10 are energized, they generate a supporting force with the rotor under test, suspending the rotor. The stator of the drive motor 9 drives the rotor to rotate relative to the induction copper sleeve. The system also includes a drive motor frequency converter 7 and a magnetic levitation bearing controller 8 connected to the drive motor and magnetic levitation bearings 10 respectively, and an eddy current displacement sensor 4 and a speed sensor 5 connected to an industrial control computer 1 via a data acquisition instrument 2. The eddy current displacement sensor 4, which tests the radial displacement of the rotor under test, and the speed sensor 5, which tests the overall speed of the rotor under test, are both connected to a data analyzer 6. The drive motor frequency converter 7 and the magnetic levitation bearing controller 8 are connected to the industrial control computer 1 via a 485 communication module 3. During the rotation of the rotor under test, the magnetic levitation bearing controller 8 can identify the unbalanced force of the rotor and suppress rotor vibration by applying a counterforce to the rotor.

[0027] The industrial computer 1 first drives the magnetic levitation bearing controller 8 to work. After the magnetic bearing is energized to levitate the rotor under test, the rotor can be rotated by the drive motor 9. The stator of the magnetic levitation bearing 10 is energized to generate a magnetic field, which generates a force with the rotor of the magnetic levitation bearing 10. The rotor of the magnetic levitation bearing 10 and the rotor under test are integrated, so after the stator of the magnetic levitation bearing 10 is energized, it can generate a force with the rotor under test to levitate it. The function of the induction copper sleeve is to make the rotor interact with the drive motor inverter 7 to make the rotor rotate.

[0028] Reference Figure 2 As shown, this invention discloses a rotor dynamic balancing test method based on magnetic levitation bearings, including a dynamic balancing system test procedure and a dynamic balancing accuracy level calculation method.

[0029] Step 1: After the drive motor 9 starts running, the industrial control computer 1 drives the magnetic levitation bearing controller 8 through the 485 communication module 3. After the two magnetic levitation bearings 10 are energized, the force applied to the induction copper sleeve makes the rotor under test levitate. Then, the air gap between the stator and rotor of the two magnetic levitation bearings 10 in the X and Y directions is recorded. x a 、x b 、y a 、y b and current i xa 、i xb、 i ya 、i ybThe supporting force of the magnetic levitation bearing 10 can be obtained based on the air gap between the stator and rotor and the current value.

[0030] Step 2: The industrial control computer 1 sends a frequency conversion command to the drive motor inverter 7 through the 485 communication module 3. The drive motor 9 rotates according to the applied frequency, the rotor under test rotates, and the drive motor 9 does not rotate.

[0031] Step 3: After the rotor under test is running stably, the industrial control computer 1 controls the data acquisition instrument 2 to record and save the radial amplitude and speed of the rotor under test through two sets of four eddy current displacement sensors 4 and one speed sensor 5, and send them to the data analyzer 6.

[0032] Step 4, refer to Figure 3 As shown, the structural model of the rotor under test is first established: based on the X-direction function f(i,x)=k of the electromagnetic force, current, and displacement of the magnetic levitation bearing 10. ix Ik x x and y direction functions f(i,y)=k iy Ik y y, where f(i,x) is the electromagnetic force on the magnetic levitation bearing 10 in the X direction, f(i,y) is the electromagnetic force on it in the Y direction, and k ix and k iy Let k be the current stiffness in the X and Y directions. x x and k y Let y be the displacement stiffness in the X and Y directions. The force formula for balancing the weight and electromagnetic force on the rotor under test when the magnetic levitation bearing 10 is statically suspended is obtained. Then, based on the actual structural model of the rotor under test, the distances g and h from the two magnetic levitation bearings 10 to the nearest eddy current displacement sensor 4, as well as the distances i and j between the two magnetic levitation bearings 10 at positions AB and the correction surface, and the radii r1 and r2 of the correction mass are input into the data analysis software of the data analyzer 6.

[0033] Step 5: The industrial control computer 1 performs dynamic balance calculations based on the data saved by the data acquisition instrument 2 and the radial vibration data and rotational speed collected by the data analysis instrument 6, according to the data collected by the control data analysis software. The magnitude and phase of the correction mass are obtained, and the dynamic balance accuracy level of the rotor under test is calculated.

[0034] Reference Figure 4 As shown, the dynamic balancing accuracy level is calculated using the following dynamic balancing calculation formula:

[0035] The vector is formed by the coordinates collected by the four eddy current displacement sensors 4 and the speed sensors 5 at positions A and B. and the centroid coordinates of the rotor under test Combined force formulas and We can solve for a, b, c, d, e, and f: ,

[0036] Where x seA y seA The radial displacement of eddy current displacement sensor 4 at position A in the X and Y directions is given by x. seB y seB The radial displacement of eddy current displacement sensor 4 at position B in the X and Y directions is given by x. seA1 y seA1 Let x be the rotor radial displacement of the magnetic levitation bearing 10 at point A in the X and Y directions. seB1 y seB1 Let B be the radial displacement of the rotor of the magnetic levitation bearing 10 in the X and Y directions, and let the rotor coordinates be represented as x, y, ... and β, where β and y are the angles at which the rotor rotates counterclockwise around the x and y axes, respectively.

[0037] Let the force vector of the magnetic levitation bearing 10 be... The force and torque of the bearing under the vector q can be expressed as: ,in The dynamic equation of the rotor considering the unbalance. Where U is the unbalanced centrifugal force matrix of the rotor. In the formula, θ1 and θ2 are the angles between the correction mass and the X-axis on the two correction surfaces A and B, respectively, which are obtained after Laplace transform. After further conversion ,

[0038] Based on the rotor speed n and rotor radial amplitude x measured by data acquisition instrument 2 seA1 y seA1 x seB2 y seB2 The currents in the X and Y directions of the magnetic levitation bearing, and the air gap between the stator and rotor, are used to solve for the corrected masses m1 and m2 and the corrected phases θ1 and θ2. Further calculations are then performed to obtain the dynamic balance accuracy level. .

[0039] The above description is merely for illustrative purposes and not intended to limit the scope of the invention. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments. Those skilled in the art should understand that any modifications or equivalent substitutions that do not depart from the spirit and scope of the invention are covered within the scope of the claims of the invention.

Claims

1. A test method for a dynamic balancing test system for an electric motor rotor, characterized in that, The motor rotor dynamic balancing test system includes a drive motor (9) connected to the rotor under test, an induction copper sleeve set at the shaft extension end of the rotor under test, and two magnetic levitation bearings (10) serving as rotor support units. It also includes a drive motor inverter (7) and a magnetic levitation bearing controller (8) connected to the drive motor (9) and the magnetic levitation bearings (10) respectively, as well as a speed sensor (5) and multiple eddy current displacement sensors (4) connected to an industrial control computer (1) via a data acquisition instrument (2). The speed sensor (5) and the eddy current displacement sensors (4) are also connected to a data analyzer (6). The drive motor inverter (7) and the magnetic levitation bearing controller (8) are connected to the industrial control computer (1) via a 485 communication module (3). The system includes the following steps: Step 1: The industrial control computer (1) drives the magnetic levitation bearing controller (8) through the 485 communication module (3). After the magnetic levitation bearing (10) is powered on, the force applied to the rotor under test makes the rotor under test float. Then, the air gap between the stator and rotor of the two magnetic levitation bearings (10) in the X and Y directions is recorded. x a 、x b 、y a 、y b and current i xa 、i xb、 i ya 、i yb ; Step 2, the industrial control computer (1) sends a frequency conversion command to the drive motor inverter (7) through the 485 communication module (3), and the rotor under test rotates; Step 3: After the rotor under test is running stably, the industrial control computer (1) controls the data acquisition instrument (2) to record and save the radial amplitude and speed of the rotor under test through two sets of four eddy current displacement sensors (4) and speed sensors (5), and send them to the data analyzer (6). Step 4, first establish the structural model of the rotor to be tested: based on the X-direction function f(i,x)=k of the electromagnetic force, current and displacement of the magnetic levitation bearing (10). ix Ik x x and y direction functions f(i,y)=k iy Ik y y, where f(i,x) is the electromagnetic force on the magnetic levitation bearing (10) in the X direction, f(i,y) is the electromagnetic force on the bearing in the Y direction, and k ix and k iy Let k be the current stiffness in the X and Y directions. x x and k y Let y be the displacement stiffness in the X and Y directions. The force formula for balancing the weight and electromagnetic force on the rotor when the magnetic levitation bearing (10) is statically suspended is obtained. ; Then, based on the structural model of the rotor under test, input the distances g and h from the two magnetic levitation bearings (10) to the nearest eddy current displacement sensor (4), as well as the distances i and j between the two magnetic levitation bearings (10) at position AB and the correction surface, and the radii r1 and r2 of the correction mass in the data analyzer (6); Step 5: The industrial control computer (1) performs dynamic balance calculation based on the data saved by the data acquisition instrument (2) and the radial amplitude and rotational speed collected by the data analyzer (6), obtains the magnitude and phase of the correction mass, and calculates the dynamic balance accuracy level of the rotor under test.

2. The testing method of a rotor dynamic balancing test system according to claim 1, wherein, Step 5 uses the following dynamic balancing calculation formula to calculate the dynamic balancing accuracy level: The vector formed by the coordinates collected by the eddy current displacement sensor (4) and the speed sensor (5) and the centroid coordinates of the rotor under test Combined force formulas and It can be solved a, b, c, d, e, f : ,in x seA 、y seA The radial displacement in the X and Y directions of the eddy current displacement sensor (4) at position A is given. x seB 、y seB For the radial displacement in the X and Y directions of the eddy current displacement sensor (4) at position B, x seA1 、y seA1 The radial displacement of the rotor in the X and Y directions of the magnetic levitation bearing (10) at point A is given. x seB1 、 y seB1 The radial displacement of the rotor in the X and Y directions of the magnetic levitation bearing (10) at point B is represented by the rotor coordinates x, y, ... and β, where β and β are the angles by which the rotor rotates counterclockwise around the x and y axes, respectively; Let the force vector of the magnetic levitation bearing (10) be The bearing force is q The force and torque under a vector are expressed as follows: ,in The dynamic equation of the rotor , U The unbalanced centrifugal force matrix of the rotor , In the formula, θ1, θ2 are respectively A, B The correction quality on the two correction planes X The angle between the axis and the plane, after the Laplace transformation After further conversion , Based on the rotor speed n and rotor radial amplitude measured by the data acquisition instrument (2) x seA1 、y seA1 x seB2 、y seB2 The current in the X and Y directions of the magnetic levitation bearing (10), the air gap between the stator and rotor, and the corrected masses m1 and m2 and the corrected phases θ1 and θ2 are obtained by solving the problem. The dynamic balance accuracy level is then calculated. .

Images