A high-precision dynamic balance correction device and method for a magnetic suspension rotor

Abstract

The application discloses a kind of high-precision dynamic balance correction device and method of magnetic suspension rotor, and the application relates to the technical field of high-speed magnetic suspension motor, including hardware-in-the-loop simulation system.The hardware-in-the-loop simulation system includes high-speed magnetic suspension motor and its magnetic suspension motor controller constitute the physically existing hardware system of the hardware-in-the-loop simulation system, further including magnetic suspension motor dynamic mathematical model, magnetic suspension control system and dynamic unbalance parameter computer optimization algorithm constitute the simulation system existing in computer digital space in the hardware-in-the-loop system;With the mechanical, electromagnetic and control system structure of high-speed magnetic suspension motor itself, the equivalent dynamic unbalance parameter of magnetic suspension motor rotor assembly is determined by signal acquisition, system simulation and computer artificial intelligence parameter optimization method to realize the dynamic balance correction of rotor assembly, improve the efficiency of turbine compressor, and simultaneously reduce the effect of production cost.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high-speed magnetic suspension motors, in particular to a high-precision dynamic balance correction device and method for a magnetic suspension rotor. BACKGROUND

[0002] The rotor of a high-speed magnetic suspension motor rotates in a suspended state under the action of the electromagnetic force of a magnetic suspension bearing, and thus has the advantages of no mechanical wear, no lubricating oil pollution, low energy consumption, low noise and long service life. Therefore, the high-speed magnetic suspension motor is increasingly replacing traditional mechanical bearing motors in application scenarios with special requirements for high speed, high efficiency, vacuum and ultra-cleanliness. One of the main application fields of the high-speed magnetic suspension motor is various types of high-speed turbomachinery, such as centrifugal air compressors and centrifugal refrigerant compressors. The most important feature of high-speed centrifugal compressor equipment driven by a high-speed magnetic suspension motor is high efficiency. Compared with traditional compressors of other forms, the power energy saving of the high-speed centrifugal compressor driven by the high-speed magnetic suspension motor can reach 20-40%. One of the key factors for the high-speed centrifugal compressor to achieve substantial energy saving is the high-precision position control of the magnetic suspension rotor assembly (including the rotating body of components such as the turbine wheel, the motor rotor and the magnetic suspension bearing rotor magnetic circuit) in a suspended state. One of the key conditions for achieving high-precision position control is that the manufacturing process of the rotor assembly can achieve high-level dynamic balance accuracy. It is inevitable that the rotor assembly has a certain degree of dynamic balance imbalance in the manufacturing process. In a high-speed motor using a traditional mechanical bearing, the rotor rotates around the geometric centerline of the bearing under the constraint of the mechanical bearing. The dynamic balance imbalance existing in the rotor will generate a periodic radial centrifugal force when the rotor rotates. In the case of excessive dynamic balance imbalance, it will cause synchronous oscillation of the motor and accelerate the wear of the bearing. In the case of using a magnetic suspension bearing in a high-speed motor, the rotor has a certain displacement space in the electromagnetic bearing. Therefore, in the case of dynamic balance imbalance of the rotor, the rotating shaft of the rotor can be made to coincide with the inertia shaft by the electromagnetic bearing control system, so as to reduce or even eliminate the oscillation caused by the radial centrifugal force. However, the actual rotating axis of the rotor deviates from the designed rotating axis.

[0003] In order to avoid the rubbing between the turbine wheel and the volute due to the deviation of the rotating axis, the gap between the turbine wheel and the volute needs to be increased in the design. However, the increase of the gap will lead to the reduction of the efficiency of the compressor. Therefore, high-precision dynamic balance of the rotor is crucial for improving the efficiency of the turbine compressor.

[0004] The conventional method for obtaining a high-precision dynamically balanced rotor assembly is to use a high-speed high-precision dynamic balancing machine to implement dynamic balance correction on the rotor assembly during the manufacturing process of the rotor assembly. However, the high-speed high-precision dynamic balancing machine is usually expensive and difficult to obtain. Therefore, it is of great significance for product research and development, production and performance improvement of the related industry to achieve high-precision dynamic balance correction of the rotor assembly of the high-speed magnetic suspension motor in a low-cost and easy-to-obtain manner. SUMMARY

[0005] The present application aims to provide a kind of magnetic suspension rotor high-precision dynamic balance correction device and method, with the mechanical, electromagnetic and control system structure of high-speed magnetic suspension motor itself is utilized, the equivalent dynamic imbalance parameters of magnetic suspension motor rotor assembly are determined by signal acquisition, system simulation and computer artificial intelligence parameter optimization method to realize the dynamic balance correction of rotor assembly, improve the efficiency of turbine compressor, and simultaneously reduce the effect of production cost, solve the problems mentioned in the above background art.

[0006] To achieve the above object, the present application provides the following technical scheme: a kind of magnetic suspension rotor high-precision dynamic balance correction device, including hardware-in-the-loop simulation system, the hardware-in-the-loop simulation system includes high-speed magnetic suspension motor and its magnetic suspension motor controller constitutes the physically existing hardware system of the hardware-in-the-loop simulation system, also includes magnetic suspension motor dynamic mathematical model, magnetic suspension control system and dynamic imbalance parameter computer optimization algorithm constitute the simulation system existing in computer digital space in the hardware-in-the-loop system;

[0007] The high-speed magnetic suspension motor includes magnetic suspension rotor assembly, radial electromagnetic bearing, rotor assembly radial displacement sensor for detecting the position of the magnetic suspension rotor assembly in electromagnetic bearing air gap, three-phase motor stator, axial electromagnetic bearing and magnetic suspension rotor assembly angular displacement sensor;The magnetic suspension motor controller includes rotor assembly radial displacement sensor signal processing circuit, electromagnetic bearing PWM power amplifier, magnetic suspension rotor assembly angular displacement signal processing circuit, magnetic suspension position closed-loop controller, motor PWM drive and controller.

[0008] Optionally, the magnetic suspension rotor assembly is a rigid body of rotation composed of turbine impeller, radial magnetic suspension bearing rotor magnetic circuit, motor rotor, rotor assembly radial displacement sensor electromagnetic target ring, dynamic balance weight reduction area, axial magnetic suspension bearing rotor and other components.

[0009] Optionally, the radial electromagnetic bearing, the axial electromagnetic bearing, the rotor assembly radial displacement sensor, the magnetic suspension position closed-loop controller and its attached sensor signal processing circuit and power amplification circuit jointly constitute the magnetic suspension control system of the rotor assembly.

[0010] Optionally, the three-phase motor stator, the rotor and the motor PWM drive and the controller constitute the axial rotation control system of the magnetic suspension rotor assembly, and the axial electromagnetic bearing, the axial magnetic suspension bearing rotor and the axial position component control in the magnetic suspension position closed-loop controller constitute the axial position control system of the rotor assembly.

[0011] Optionally, the magnetic suspension rotor assembly is designed to have a ring belt at both ends for dynamic balance correction machining.

[0012] Optionally, the radial position closed-loop control algorithm of the magnetic suspension motor controller is a reverse dynamics control algorithm.

[0013] Optionally, the inertia product elements of the rotor inertia matrix of the dynamic mathematical model of the magnetic suspension motor are functions of the dynamic balance imbalance parameters of the rotor assembly, the dynamic balance imbalance parameters are a 3D vector composed of a mass representing static imbalance, a mass representing dynamic imbalance, and an angle representing the mass distribution, and the dynamic mathematical model of the magnetic suspension motor includes functional modules simulating the dynamic characteristics of the magnetic suspension bearing current control loop and the dynamic characteristics of the rotor assembly radial position sensor.

[0014] Optionally, the dynamic balance imbalance parameter computer optimization algorithm is to extract the synchronous components with the same frequency as the rotation of the rotor assembly from the magnetic suspension bearing electromagnet currents in the actual physical system and the computer simulation system respectively, and the vector difference between the two is used to form the objective function of the computer optimization algorithm.

[0015] Optionally, the synchronous component is obtained by rotating the magnetic suspension bearing electromagnet current vector from the stationary coordinate system to the rotor rotating coordinate system and low-pass filtering.

[0016] A use method of a magnetic suspension rotor high-precision dynamic balance correction device, comprising the following steps:

[0017] S1: The magnetic suspension rotor assembly is supported without contact between the electromagnets of the magnetic suspension bearing and the geometric center line of the magnetic suspension rotor assembly is aligned with the geometric center line of the electromagnets;

[0018] S2: The magnetic suspension rotor assembly rotates in a suspended state under the control of the motor PWM drive and controller;

[0019] S3: The equivalent dynamic balance imbalance parameters of the magnetic suspension rotor assembly are determined by the method of signal acquisition, system simulation and computer artificial intelligence parameter optimization to realize dynamic balance correction of the magnetic suspension rotor assembly.

[0020] Compared with the prior art, the beneficial effects of the present application are as follows:

[0021] Firstly, the present application determines the equivalent dynamic balance imbalance parameters of the magnetic suspension motor rotor assembly by using the mechanical, electromagnetic and control system structure of the high-speed magnetic suspension motor, and realizes dynamic balance correction of the rotor assembly by the method of signal acquisition, system simulation and computer artificial intelligence parameter optimization, thereby improving the efficiency of the turbine compressor and reducing production cost.

[0022] Secondly, the application sets the function module to adopt the inertial filter structure, but is not limited to the inertial filter structure, the filter time constant is set according to the bandwidth and the transmission delay of the magnetic suspension bearing current control loop and the rotor assembly radial position sensor in the actual system, so that the dynamic characteristics of the simulation system are closer to the actual system. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the front view of the structure of the application;

[0024] Figure 2 It is the schematic diagram of the high-speed magnetic suspension motor structure of the application;

[0025] Figure 3 It is the schematic diagram of the magnetic suspension rotor assembly structure of the application;

[0026] Figure 4 a is the schematic diagram of the coordinate system related to the radial motion control of the rotor assembly in the electromagnetic bearing of the application;

[0027] b is the schematic diagram of the six motion freedoms or motion state variables of the rotor assembly relative to the inertial coordinate system when the rotor assembly is in the suspended state;

[0028] c is the schematic diagram of the intersection coordinate vector of the geometric center axis of the rotor assembly and the sensor coordinate system plane and the vector diagram of the electromagnetic force of the bearing in the bearing coordinate system plane;

[0029] Figure 5 a is the schematic diagram of the relative position relationship between the geometric center axis of the rotor assembly and the geometric center line of the electromagnetic body of the magnetic suspension bearing when the ideal dynamic balance;

[0030] b is the schematic diagram of the relative position relationship between the geometric center axis of the rotor assembly and the geometric center line of the electromagnetic body of the magnetic suspension bearing when the dynamic balance is unbalanced;

[0031] Figure 6 It is the structural block diagram of the radial control part of the magnetic suspension control system in the hardware-in-the-loop hardware system;

[0032] Figure 7 It is the structural block diagram of the rotor assembly dynamic simulation model in the hardware-in-the-loop simulation system;

[0033] Figure 8 a is the schematic diagram of the dynamic balance unbalance of the equivalent mass of the rotor assembly on the dynamic balance correction ring of the application;

[0034] b is the position parameter schematic diagram of the equivalent mass on the dynamic balance correction ring of the rotor assembly;

[0035] c is the schematic diagram of the dynamic balance unbalance of the rotor assembly by using the static unbalance mass, the dynamic unbalance mass and the angle representing the mass distribution;

[0036] Figure 9 The total implementation block diagram of the dynamic balance correction device for the hardware-in-the-loop simulation of the magnetic suspension motor rotor of the application.

[0037] In the figure: 1, high-speed magnetic suspension motor; 2, magnetic suspension motor controller; 3, dynamic mathematical model of magnetic suspension motor; 4, magnetic suspension control system; 5, computer optimization algorithm for dynamic imbalance parameters; the high-speed magnetic suspension motor (1) comprises: 1_1, magnetic suspension rotor assembly; 1_2, radial electromagnetic bearing; 1_3, rotor assembly radial displacement sensor; 1_4, three-phase motor stator; 1_5, axial electromagnetic bearing; 1_6, magnetic suspension rotor assembly angular displacement sensor, as shown in Figure 2 ; the high-speed magnetic suspension motor controller 2 comprises: 2_1, rotor assembly radial displacement sensor signal processing circuit; 2_2, electromagnetic bearing current PWM power amplifier; 2_3, magnetic suspension rotor assembly angular displacement signal processing circuit; 2_4, magnetic suspension position closed-loop controller; 2_5, motor PWM drive and controller, as shown in Figure 2 ; the magnetic suspension rotor assembly 1_1 comprises: 1_1_1, turbine impeller; 1_1_2, radial magnetic suspension bearing rotor magnetic circuit; 1_1_3, motor rotor; 1_1_4, rotor assembly radial displacement sensor electromagnetic target ring; 1_1_5, dynamic balance weight reduction area; 1_1_6, axial magnetic suspension bearing rotor, as shown in Figure 3 . DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0039] Please refer to Figures 1 to 9 , the embodiment provides a high-precision dynamic balance correction device for a magnetic suspension rotor, which comprises a hardware-in-the-loop simulation system. The hardware-in-the-loop simulation system comprises a physically existing hardware system of the hardware-in-the-loop simulation system, which is composed of a high-speed magnetic suspension motor 1 and a magnetic suspension motor controller 2 of the high-speed magnetic suspension motor 1. The hardware-in-the-loop simulation system further comprises a simulation system existing in a computer digital space in the hardware-in-the-loop system, which is composed of a dynamic mathematical model 3 of the magnetic suspension motor, a magnetic suspension control system 4, and a computer optimization algorithm 5 for dynamic imbalance parameters.

[0040] The high-speed magnetic suspension motor 1 comprises a magnetic suspension rotor assembly 1_1, a radial electromagnetic bearing 1_2, a rotor assembly radial displacement sensor 1_3 for detecting the position of the rotor assembly in the electromagnetic bearing air gap, a three-phase motor stator 1_4, an axial electromagnetic bearing 1_5, and a magnetic suspension rotor assembly angular displacement sensor 1_6; the magnetic suspension motor controller 2 comprises a rotor assembly radial displacement sensor signal processing circuit 2_1, an electromagnetic bearing PWM power amplifier 2_2, a magnetic suspension rotor assembly angular displacement signal processing circuit 2_3, a magnetic suspension position closed-loop controller 2_4, and a motor PWM drive and controller 2_5.

[0041] More specifically, in the present embodiment, the operation process of the device is to determine the equivalent dynamic unbalance parameters of the magnetic suspension motor rotor assembly by means of signal acquisition, system simulation, and computer artificial intelligence parameter optimization, so as to realize dynamic balance correction of the rotor assembly by utilizing the mechanical, electromagnetic, and control system structure of the high-speed magnetic suspension motor 1 itself.

[0042] It is inevitable for the magnetic suspension rotor assembly 1_1 to have a certain degree of dynamic unbalance in the manufacturing process, and severe dynamic unbalance will cause the rotor assembly to shake during high-speed rotation, thereby reducing the performance, efficiency, and service life of the equipment. When the magnetic suspension rotor assembly 1_1 has dynamic unbalance, it will generate a radial centrifugal force in the rotating state to force the geometric center line of the rotor assembly to deviate from the geometric center line of the electromagnet of the magnetic suspension bearing, and the magnetic suspension position closed-loop controller 2_4 outputs an action force opposite to the centrifugal force to try to make the rotor assembly rotate in a set state. Therefore, the output of the magnetic suspension position closed-loop controller 2_4 carries the information of the dynamic unbalance of the rotor assembly.

[0043] In the present application, the method for extracting the dynamic unbalance information is to establish a mathematical model of the magnetic suspension control system of the measured magnetic suspension rotor assembly 1_1, to obtain the controller output under the same operating conditions as the actual magnetic suspension rotor assembly 1_1 through system simulation, and to correct the inertia product elements of the inertia matrix of the rotor assembly 1_1 mathematical model through computer iterative optimization algorithm when there is an error between the simulation obtained control output and the control output collected from the actual magnetic suspension control system, so as to make the error between the simulation obtained control output and the control output of the actual magnetic suspension control system converge to a minimum value, and the inertia matrix inertia product element correction value corresponding to the minimum error is the dynamic unbalance parameter of the actual rotor assembly.

[0044] Further, in the present embodiment, the magnetic suspension rotor assembly 1_1 is a rigid body of rotation composed of a turbine impeller 1_1_1, a radial magnetic suspension bearing rotor magnetic circuit 1_1_2, a motor rotor 1_1_3, a rotor assembly radial displacement sensor electromagnetic target ring 1_1_4, a dynamic balance weight reduction area 1_1_5, and an axial magnetic suspension bearing rotor 1_1_6.

[0045] More specifically, in this embodiment, after the dynamic balance unbalance parameters are obtained, the corresponding weight removal machining is performed on the dynamic balance weight removal area 1_1_5 by machining, i.e. the dynamic balance correction of the rotor assembly 1_1 is completed.

[0046] Further, in this embodiment: the radial electromagnetic bearing 1_2, the rotor assembly radial displacement sensor 1_3, the magnetic levitation position closed-loop controller 2_4 and its attached sensor signal processing circuit and power amplification circuit jointly constitute the magnetic levitation radial position control system of the magnetic levitation rotor assembly 1_1.

[0047] Further, in this embodiment: the three-phase motor stator 1_4, the rotor 1_1_3 and the motor PWM drive and controller 2_5 constitute the axial rotation control system of the rotor assembly 1_1, the axial electromagnetic bearing 1_5, the axial magnetic levitation bearing rotor 1_1_6 and the axial position component control in the magnetic levitation position closed-loop controller 2_4 constitute the axial position control system of the magnetic levitation rotor assembly 1_1, and the axial rotation control system and the axial position control system are indispensable parts of the high-speed magnetic levitation motor system.

[0048] Further, in this embodiment: the magnetic levitation rotor assembly 1_1 is designed to have a ring belt at both ends for dynamic balance correction machining, and the radial position closed-loop control algorithm of the magnetic levitation motor controller 2 is a kind of inverse dynamics control algorithm.

[0049] More specifically, in this embodiment, the radial position closed-loop control algorithm is a control structure using proportional-derivative control, rotor gyroscopic effect compensation and magnetic levitation bearing negative stiffness characteristic compensation according to the radial motion rigid body mathematical model of the rotor assembly, the radial position closed-loop control algorithm is used for realizing the rotor assembly dynamic balance unbalance detection, and the position closed-loop control task is to make the geometric center axis of the rotor assembly coincide with the geometric center line of the magnetic levitation bearing electromagnet and rotate at a constant speed without exceeding the position closed-loop control bandwidth.

[0050] Further, in this embodiment: the inertia product elements of the rotor inertia matrix of the magnetic levitation motor dynamic mathematical model 3 are functions of the rotor assembly dynamic balance unbalance parameters, the dynamic balance unbalance parameters are a 3-dimensional vector composed of a mass representing static unbalance, a mass representing dynamic unbalance and an angle representing mass distribution, and the magnetic levitation motor dynamic mathematical model 3 includes functional modules simulating the dynamic characteristics of the magnetic levitation bearing current control loop and the dynamic characteristics of the rotor assembly radial position sensor.

[0051] More specifically, in the embodiment, the function module for simulating the dynamic characteristics of the magnetic suspension bearing current control loop and the dynamic characteristics of the rotor assembly radial position sensor adopts, but is not limited to, an inertial filter structure, a filter time constant of which is set according to the bandwidth and the transmission delay of the magnetic suspension bearing current control loop and the rotor assembly radial position sensor in the actual system, so that the dynamic characteristics of the simulation system are closer to those of the actual system.

[0052] Further, in the embodiment, the computer optimization algorithm 5 for calculating the dynamic balance unbalance parameters is to extract the synchronous components with the same frequency as the rotation of the rotor assembly from the magnetic suspension bearing electromagnet currents in the actual physical system and the computer simulation system respectively, and to use the vector difference of the two to form the objective function of the computer optimization algorithm.

[0053] More specifically, in the embodiment, the computer optimization algorithm 5 for calculating the dynamic balance unbalance parameters adopts, but is not limited to, the Hookes-Jeeves algorithm as the search engine of the computer optimization, and the synchronous components are obtained by rotating the magnetic suspension bearing electromagnet current vector from the stationary coordinate system to the rotor rotating coordinate system and then low-pass filtering.

[0054] Referring to Figures 1 to 9 , the application provides a use method of the high-precision dynamic balance correction device for the magnetic suspension rotor, including the following steps:

[0055] S1: supporting the magnetic suspension rotor assembly 1_1 between the electromagnets of the magnetic suspension bearing without contact and making the geometric center line of the magnetic suspension rotor assembly 1_1 coincide with the geometric center line of the electromagnets;

[0056] S2: rotating the magnetic suspension rotor assembly 1_1 at a constant speed in a suspended state under the control of the motor PWM driver and controller 2_5;

[0057] S3: determining the equivalent dynamic balance unbalance parameters of the magnetic suspension rotor assembly 1_1 by the method of signal acquisition, system simulation and computer artificial intelligence parameter optimization, so as to realize the dynamic balance correction of the magnetic suspension rotor assembly 1_1.

[0058] Specific description and operation principle:

[0059] (1) The radial motion control of the magnetic suspension rotor assembly (1_1) in the electromagnetic bearing involves four coordinate systems, as shown in Figure 4 .a. Among them, the o i _x i y i z i coordinate system is the inertial coordinate system fixed with the electromagnets of the magnetic suspension bearing, or the stationary coordinate system; the o r _x r y r z rA coordinate system fixed with the rotor assembly, o r In ideal case, coincides with the center of gravity COG of the rotor assembly, o r _x r y r z r Also called COG coordinate system; o a _y a z a And o b _y b z b Jointly constitute the bearing coordinate system in which the electromagnetic force vector of the magnetic bearing lies; o as _y as z as And o bs _y bs z bs Jointly constitute the sensor coordinate system in which the rotor position sensor lies. The rotor assembly has 6 degrees of freedom of motion, or motion state variables, relative to the inertial coordinate system o Figure 4 .b when in levitation state, as shown in the following figure. Among them, [x r y r z r and [φ ψ θ] are the translational and rotational motion state variables of the rotor assembly relative to the inertial coordinate system o i _x i y i z i . Among the above 6 motion state variables, the motion state variables x r (t) and φ(t) representing the axial translation and rotation can be controlled independently in general case, and the influence of the radial motion of the rotor can be ignored, so the realization of the axial rotation control and displacement control will not be analyzed in detail in the following text of the present application. The remaining 4 motion state variables y r ,z r ,ψ,θ of the rotor assembly constitute the radial motion state variables q = [y r z r ψθ] T in the COG coordinate system.

[0060] The radial electromagnetic force vector of the magnetic bearing can be converted from the bearing coordinate system to the rotor COG coordinate system by the following linear transformation

[0061] F COG =BU f

[0062] Wherein

[0063] U f =[f ay f by faz f bz ] T For the bearing coordinate system o a _y a z a and o b _y b z b Radial electromagnetic force vector F of the medium magnetic levitation bearing COG =[f ry f rz τ ψ τ θ ] T Mapping the radial electromagnetic force vector of a magnetic levitation bearing to the generalized force vector in the COG coordinate system

[0064] The radial motion state variables of the COG coordinate system are represented by the linear transformation matrix.

[0065] q = [y r z r ψ θ] T

[0066] This can be equivalently represented by the geometric center axis of the rotor assembly and the sensor coordinate system plane o. as _y as z as and o bs _y bs z bs The intersection point o ras and o rbs coordinate vector

[0067] q s =[y as z as y bs z bs ] T

[0068] To indicate, such as Figure 4 As shown in .c), the equivalent motion state variable q s The measurement is performed in the sensor coordinate system o as _y as z as and o bs _y bs z bs Implemented in [the system], the measured state variable q s The following linear transformation can be used to map to the rotor COG coordinate system.

[0069] q = C -1 q s

[0070] in

[0071] Its inverse matrix C -1 The sensor coordinate system o as _y as z as And the state variable in o bs _y bs z bs The transformation matrix of the coordinate system to COG.

[0072] In the ideal case, the rotor assembly rotates around its geometric center axis x r o r It is also the principal axis of inertia, and the geometric center axis of the rotor coincides with the geometric center line x i o i Of the electromagnetic body, as shown in Figure 5 .a.When the rotor has dynamic imbalance, the center of gravity of the rotor deviates from its geometric axis, and the geometric center axis x r o r Of the rotor no longer coincides with its principal axis of inertia, as shown in Figure 5 .b.According to the translation theory of inertia, the deviation of the center of gravity of the rotor can be equivalent to the mass Δm a And Δm b Located in the plane of the two ends of the rotor in the magnetic suspension bearing coordinate system o a _y a zx and o b _y b z b When the rotor assembly rotates around its geometric axis under the control of the magnetic suspension control system, the rotor assembly will bear the radial centrifugal force perpendicular to the rotation axis caused by the deviation of the center of gravity, and the direction of the centrifugal force rotates around the geometric center line of the electromagnetic body synchronously with the rotor assembly and tries to make the geometric center axis of the rotor deviate from the geometric center line of the electromagnetic body. In order to keep the geometric center axis of the rotor coinciding with the geometric center line of the electromagnetic body, the magnetic suspension control system must output a force in the opposite direction of the radial centrifugal force with the same amplitude to try to keep the rotor assembly in the ideal motion posture, as shown in Figure 5 .b.F a ,F b Therefore, the synchronous rotation component in the output of the magnetic suspension control system carries the information of the deviation of the center of gravity of the rotor assembly, and by processing and analyzing the information by appropriate methods, the specific parameters of the dynamic imbalance of the rotor assembly can be obtained. The present application obtains the specific parameters of the dynamic imbalance of the rotor assembly by hardware-in-the-loop simulation and computer artificial intelligence parameter optimization method.

[0073] (2) The structure block diagram of the radial control part of the magnetic suspension control system in the hardware-in-the-loop "hardware" system is shown in Fig. 2. The controlled object is a magnetic suspension system composed of a radial magnetic suspension bearing and a rotor assembly. The linearized dynamic mathematical model of the system considering only the radial motion is: Figure 6

[0074]

[0075] q s = Cq

[0076] wherein q, q s , U f , B, C are defined as before.

[0077] is the generalized mass matrix of the rotor assembly, m is the mass of the rotor assembly, I yy is the y r axis moment of inertia of the rotor assembly.

[0078] is the gyroscopic effect matrix, wherein I xx is the x r axis moment of inertia of the rotor assembly, and Ω is the rotational speed of the rotor assembly.

[0079] U f = -K g q s + K i I MB is the mathematical model of the radial force of the magnetic suspension bearing,

[0080] wherein

[0081] is the position negative stiffness matrix of the magnetic suspension bearing, K ga and K gb are the position negative stiffness coefficients of the front and rear magnetic suspension bearings, respectively,

[0082] is the current stiffness matrix of the magnetic suspension bearing, K ia and K ib are the current stiffness coefficients of the front and rear magnetic suspension bearings, respectively,

[0083] I MB = [i ay i by i az i bz ] T is the current vector of the magnetic suspension bearing, and is also the control output of the magnetic suspension control system.

[0084] ​(3) In the present application, in order to realize that the rotor assembly rotates around its geometric center axis x r o r of the magnetic suspension control system under the control of the magnetic suspension control system, and the geometric center axis of the rotor coincides with the geometric center line x i o i of the magnetic suspension bearing electromagnet, the magnetic suspension bearing controller adopts an inverse dynamics algorithm, i.e. a structure of COG coordinate system PD control + rotor gyro effect compensation + magnetic suspension bearing position negative stiffness characteristic compensation, and the corresponding magnetic suspension controller output I MB may be expressed by the following formula

[0085]

[0086] K p =(BK i ) -1 MP COG C -1 is the proportional control gain of PD control, wherein P par , P con are the translational and rotational proportional control gains, respectively,

[0087] K d =(BK i ) -1 MD COG C -1 is the differential control gain of PD control, wherein D par , D con are the translational and rotational differential control gains, respectively,

[0088] C S =(BK i ) -1 K gCOG C -1 is the magnetic suspension bearing position negative stiffness characteristic compensation coefficient, wherein

[0089] K gCOG =BK g B T is the magnetic suspension bearing position negative stiffness matrix transformed into the COG coordinate system,

[0090] C G =(BK i ) -1 GC -1 is the rotor gyro effect compensation coefficient.

[0091] (4) The structural block diagram of the rotor assembly dynamic simulation algorithm in the hardware-in-the-loop simulation system is as shown in Figure 7The magnetic suspension controller in the rotor assembly dynamic simulation system in the present application adopts the same structure and control parameters as the controller in the actual system. The dynamic mathematical model of the rotor assembly must be able to reproduce the response of the magnetic suspension controller to dynamic imbalance through system simulation, so the radial motion linearization dynamic mathematical model for the purpose of auxiliary magnetic suspension controller design

[0092]

[0093] q s =Cq

[0094] has no longer been applicable to the purpose of dynamic imbalance simulation.

[0095] In order to be able to reproduce the response of the magnetic suspension controller to dynamic imbalance through system simulation, the present application adopts the rotor assembly dynamic mathematical model in the rotor coordinate system o r _x r y r z r :

[0096] (Newtonian motion equation)

[0097] (Eulerian motion equation)

[0098] wherein

[0099] ×-vector product operator

[0100] v-translation velocity of the center of gravity of the rotor assembly, v = [v x v y v z ] T

[0101] ω-rotational velocity of the rotor assembly, ω = [ω x ω y ω z ] T

[0102] f-translation force, f = [f x f y f z ] T

[0103] G m -gravity acting on the center of gravity of the rotor assembly in the rotor coordinate system,

[0104] τ-rotational moment, τ = [τ x τ y τ z ] T

[0105] m - Rotor assembly mass; I - Rotor assembly inertia matrix. Figure 7 Functional module G in C and G S These are used to simulate the dynamic characteristics of the magnetic levitation bearing current control loop and the rotor assembly radial position sensor, respectively. C and G S In this invention, an inertial filter structure is used. Its filtering time constant needs to be tuned according to the bandwidth and transmission delay of the magnetic levitation bearing current control loop and the rotor assembly radial position sensor in the actual system, so that the dynamic characteristics of the simulation system are closer to those of the actual system.

[0106] (5) Under ideal dynamic equilibrium, the inertia product element in the inertia matrix is ​​zero.

[0107]

[0108] When a rotor experiences dynamic imbalance, the value of the inertia product element is determined by the magnitude and distribution of the mass causing the imbalance. According to the theory of inertia translation, the actual dynamic imbalance of the rotor assembly can be represented by the rotor's ends located in the bearing coordinate system. a _y a z a and o b _y b z b The mass Δm in a and Δm b Equivalent. When the rotor assembly rotates around its geometric axis under the closed-loop control of the magnetic levitation control system, Δm a and Δm b The resulting centrifugal force will be suppressed by the electromagnetic force of the electromagnetic bearings in their respective coordinate systems. Similarly, according to the theory of inertia translation, the actual dynamic imbalance of the rotor assembly can also be expressed as the mass at both ends of the rotor assembly located on the dynamic balancing correction belts. and Equivalent, such as Figure 8 As shown in .a). and Position parameters on the dynamic balancing correction ring are as follows: Figure 8 As shown in .b. When using and When the equivalent rotor assembly is dynamically unbalanced, the inertia matrix of the rotor assembly can be expressed as:

[0109]

[0110] This is the equivalent dynamic balance imbalance parameter vector.

[0111] It should be noted that when the rotor assembly is dynamically unbalanced, the moment of inertia elements on the main diagonal of the inertia matrix will change compared to the ideal dynamic balance state. However, for the magnetic levitation motor addressed in this invention, the manufacturing precision of the rotor assembly can be guaranteed. and The change in moment of inertia is much smaller than the mass m of the rotor assembly, so the change in the moment of inertia element on the main diagonal can be ignored.

[0112] δ is a four-dimensional vector, suitable for machining parameters required for balancing on a dynamic balancing correction ring. Further analysis reveals that a three-dimensional vector is a more suitable dynamic balancing imbalance parameter for computer-aided optimization.

[0113]

[0114] in The definitions of γ are as follows: Figure 8 As shown in .c. The centrifugal force applied to the dynamic balancing belts at both ends of the rotor assembly can only cause the rotor assembly to translate, while The centrifugal forces applied at both ends of the rotor assembly form a couple, which can only generate a torque that causes the rotor assembly to rotate around its center of gravity. Therefore These represent static and dynamic imbalances, respectively. δ0 is used. 3D The expression for the inertia matrix when dynamic equilibrium is lost is:

[0115]

[0116] Using δ 3D The advantage of representing dynamic imbalance is that the computer optimization process for imbalance parameters can be completed more quickly, and the problem that the optimization process may not converge to the global optimum due to dimensional redundancy when using a four-dimensional parameter vector δ for optimization can be avoided.

[0117] Using δ 3D The dynamic balance imbalance parameters obtained after the computer optimization process is completed as parameter vectors Can be converted This allows for balance correction via machining on the dynamic balancing ring belt. According to... Figure 8 .b and Figure 8 The conversion formula between the two can be derived from .c as follows:

[0118]

[0119] (6) Figure 9 The diagram shown is the overall implementation block diagram of the magnetic levitation motor rotor hardware-in-the-loop simulation dynamic balancing correction device of the present invention. The specific implementation process of dynamic balancing detection and correction is as follows:

[0120] In the "hardware" system physically existing in the hardware-in-the-loop simulation system composed of the high-speed magnetic levitation motor (1) and its control system, the rotor assembly is controlled by the magnetic levitation motor controller to rotate around its geometric center axis x r o r at a constant rotational speed Ω, and the geometric center axis of the rotor assembly coincides with the geometric center line x i o i of the electromagnet. In this state, if the rotor assembly has dynamic unbalance, the centrifugal force caused by the dynamic unbalance will be offset by the control force generated by the rotor assembly position closed-loop control system. The control force is generated by the magnetic levitation bearing electromagnet current vector i ay i by i az i bz ] T . Since the rotor assembly rotates at a constant rotational speed Ω, i ay i by i az i bz ] T corresponding to the dynamic unbalance centrifugal force in the bearing coordinate system o and are sinusoidal functions with the same frequency as the rotational frequency Ω, and and respectively constitute the rotating vectors in the bearing coordinate system o a _y a z a and o b _y b z b synchronous with the rotation of the rotor assembly.

[0121] In order to extract the synchronous rotating components in i ay i by i az i bz ] T and simplify the computer optimization process, the following rotational transformation of the bearing coordinate system to the rotating coordinate system is introduced:

[0122]

[0123] where α r = Ωt is the rotation angle between the coordinate axes o r _y r and o i _y i , which is measured by the magnetic levitation rotor assembly angular displacement sensor (1_6).

[0124] The magnetic levitation bearing electromagnet current vector I MB= [i ay i by i az i bz ] T Performing the rotation transformation And after applying low pass filter to the result of the transformation, we can get:

[0125]

[0126] Where LPF is the low pass filter

[0127]

[0128] ω LPF is the bandwidth frequency of the low pass filter, which should be chosen much lower than Ω.

[0129] is and After the rotation transformation Then after low pass filtering in the moving coordinate system o r _x r y r z r , we get the average values, thus is a vector whose components are all DC components, which can simplify the computer optimization process. Since the vector represents the response of the magnetic suspension control system to the dynamic imbalance of the rotor assembly, it is called the imbalance response vector in this invention.

[0130] It should be noted that the centrifugal force generated by the dynamic imbalance of the rotor assembly is proportional to the square of Ω, and the amplitudes of the vectors and are also proportional to the square of Ω, that is, increasing Ω can improve the sensitivity of dynamic imbalance detection. However, in the actual hardware system, in addition to the synchronous rotation components and caused by the dynamic imbalance of the rotor assembly, the gyroscopic effect can also cause the gyroscopic rotation components in the position response vector [y as y bs z as z bs ] T The existence of the gyroscopic rotation components will affect the control of the position closed-loop feedback controller (2_4) on The extraction of the rotating component will form an interference and further affect the precision of the rotor assembly dynamic balance correction value. The amplitude of the rotating component is closely related to the algorithm and response bandwidth of the magnetic bearing controller. The reverse dynamics algorithm of the magnetic bearing controller proposed in the present application can effectively suppress the rotating component through rotor gyroscopic effect compensation, so that the rotor assembly rotation speed Ω can operate at a frequency closer to the bandwidth of the magnetic suspension closed-loop feedback controller (2_4).

[0131] It should be further pointed out that in actual magnetic suspension motor systems, the rotor position signal detected by the magnetic suspension rotor assembly radial displacement sensor (1_3) often contains a radial runout component. The main factors causing radial runout are: the difference between the circumference of the electromagnetic target ring surface of the magnetic suspension bearing rotor assembly radial displacement sensor and the geometric rotation axis of the rotor assembly, target ring surface deformation, non-uniformity of the electromagnetic properties of the material used to manufacture the target ring, etc. The radial runout component will introduce harmonic components with frequencies of Ω and / or multiples of Ω in the output of the sensor (1_3), which will also be extracted by the position closed-loop feedback controller (2_4) to form an interference and further affect the precision of the rotor assembly dynamic balance correction value.

[0132] Therefore, when implementing hardware-in-the-loop magnetic suspension rotor dynamic balance detection and correction, it is first necessary to correct the sensor to eliminate the radial runout component in the output of the sensor (1_3). The correction method can be to detect the harmonic component by a certain technical means, and then inject the detected harmonic component in reverse to offset the original harmonic component. The technical means for detecting the harmonic component can be high-precision detection tools, or through numerical analysis or automatic control algorithms, etc.

[0133] While the rotor assembly is controlled by the high-speed magnetic suspension motor (1) and its control system to rotate around its geometric center axis x r o r at a constant rotation speed Ω, and the unbalance response vector is obtained, Figure 9 the simulation system composed of the magnetic suspension motor dynamic mathematical model (3) and the magnetic suspension controller simulation in the simulation will digitally simulate the magnetic suspension motor and its control system and obtain

[0134]

[0135] In the simulation, the inertia matrix used by the high-speed magnetic suspension motor dynamic mathematical model (3) is

[0136]

[0137] Therefore, is​ The function.

[0138] The objective function of the computer-based optimization module (5) for dynamic balance and imbalance parameters in a hardware-in-the-loop system is derived from the imbalance response vector of the actual system. and the imbalance response vector of the simulation system The difference constitutes

[0139]

[0140] (7) The computer optimization process is based on δ 3D The amount The 3D space R formed by γ 3 The search finds the "best" path to approximate the objective function J(δ). 3D The dynamic balance imbalance parameter vector δ corresponding to the minimum value of ) 3D_OPT The computer optimization algorithm that implements this process falls under the category of artificial intelligence. Given the rapid development of AI today, there are multiple options that can achieve the objectives of this invention. The term "best" refers to the chosen optimization algorithm. In this invention, as one specific implementation of the computer optimization algorithm, the Hooke-Jeeves algorithm will be selected, but not limited to, as the search engine for computer optimization.

[0141] The Hooke's algorithm's optimization path consists of two movement processes: probe movement and pattern movement, hence it is also called the pattern search method. Through a recurring iterative process of probe movement → pattern movement → probe movement…, it successively approaches the extreme value of the objective function. The (k+1)th probe movement starts from the current parameter variable vector δ… 3D Starting with (k), respectively in and the positive and negative directions of the γ component with a set step size h m or h γ One-by-one perturbation, h m and h γ These represent the step sizes for mass perturbation and angle perturbation, respectively. The parameter variable vector corresponding to each perturbation is δ. 3D (k,l)(l=1,2,…,6,represents the value at δ 3D (six perturbations on the three components of (k), the perturbation of the inertia matrix corresponding to each parameter variable perturbation is I(k,l)=I(δ) 3D (k,l) is used to update the dynamic mathematical model of the rotor assembly, and the objective function J(k,l) = J(δ) caused by the perturbation is obtained through simulation. 3D The change of (k,l) determines the optimal direction of movement of the perturbation component, i.e., whether to increase, decrease, or remain unchanged. After perturbing the three components in sequence, the parameter variable vector δ can be obtained. 3D(k) the increment vector Δδ 3D (k) as a result of the probing movement.

[0142] The pattern movement is Δδ 3D (k) is not zero, then

[0143] δ 3D (k, m) = δ 3D (k) + mΔδ 3D (k), m = 1, 2, 3,...

[0144] The simulation is performed and the objective function J(k, m) = J(δ 3D (k, m)) is calculated. The condition for the completion of the pattern movement is

[0145] J(k, m) < J(k, m + 1)

[0146] i.e. the objective function no longer continues to converge in the direction of the probing movement Δδ 3D (k). The parameter vector obtained at this time will be used as the new current value

[0147] δ 3D (k + 1) = δ 3D (k) + mΔδ 3D (k)

[0148] The (k + 1)th probing movement is performed.

[0149] If the result of the probing movement Δδ 3D (k) is equal to zero, i.e. the result of the probing movement is δ 3D (k) remains stationary, it means that δ 3D (k) has approached the optimal value. At this time, the probing movement step h m and h γ can be reduced, and δ 3D (k) is returned as the current parameter vector to the probing movement stage to continue the optimization to improve the detection precision of the dynamic balance imbalance parameter. If h m and h γ have already been smaller than the set minimum step value, the computer optimization process is ended.

[0150] At this time, δ 3D (k) is the detected dynamic balance imbalance parameter vector δ 3D_OPT .

[0151] As mentioned before, δ 3D_OPT needs to be converted into a four-dimensional dynamic balance imbalance parameter vector

[0152]

[0153] To realize the balance correction on the dynamic balance correction ring belt by machining. The correction parameters when using the weight reduction method to correct the dynamic imbalance are

[0154]

[0155] Finally, the corresponding weight removal operation is performed by machining with reference to the weight reduction positions and weight reduction values, and the dynamic balance correction of the rotor assembly is completed.

Claims

1. A method of using a high precision dynamic balancing correction device for a magnetic levitation rotor, the device comprising a hardware-in-the-loop simulation system, characterized in that: The hardware-in-the-loop simulation system comprises a physically existing hardware system of a high-speed magnetic suspension motor (1) and a magnetic suspension motor controller (2) of the high-speed magnetic suspension motor (1), and a simulation system existing in a computer digital space in the hardware-in-the-loop system, which comprises a magnetic suspension motor dynamic mathematical model (3), a magnetic suspension control system (4) and a dynamic balance imbalance parameter computer optimization algorithm (5). The high-speed magnetic suspension motor (1) comprises a magnetic suspension rotor assembly (1_1), a radial electromagnetic bearing (1_2), a rotor assembly radial displacement sensor (1_3) for detecting the position of the magnetic suspension rotor assembly (1_1) in the electromagnetic bearing air gap, a three-phase motor stator (1_4), an axial electromagnetic bearing (1_5) and a magnetic suspension rotor assembly angular displacement sensor (1_6); the magnetic suspension motor controller (2) comprises a rotor assembly radial displacement sensor signal processing circuit (2_1), an electromagnetic bearing PWM power amplifier (2_2), a magnetic suspension rotor assembly angular displacement signal processing circuit (2_3), a magnetic suspension position closed-loop controller (2_4) and a motor PWM drive and controller (2_5). The use method comprises the following steps: S1: supporting the magnetic suspension rotor assembly (1_1) in a non-contact manner between electromagnets of the magnetic suspension bearing and making the geometric center line of the magnetic suspension rotor assembly (1_1) coincide with the geometric center line of the electromagnets; S2: rotating the magnetic suspension rotor assembly (1_1) in a suspended state under the control of the motor PWM drive and controller (2_5); S3: determining the equivalent dynamic balance imbalance parameters of the magnetic suspension rotor assembly (1_1) by means of signal acquisition, system simulation and computer artificial intelligence parameter optimization, so as to realize dynamic balance correction of the magnetic suspension rotor assembly (1_1).

2. The method of using a magnetic levitation rotor high precision dynamic balancing correction device according to claim 1, characterized in that: The magnetic suspension rotor assembly (1_1) is a rigid rotating body assembled by a turbine impeller (1_1_1), a radial magnetic suspension bearing rotor magnetic circuit (1_1_2), a motor rotor (1_1_3), a rotor assembly radial displacement sensor electromagnetic target ring (1_1_4), a dynamic balance weight reduction area (1_1_5), an axial magnetic suspension bearing rotor (1_1_6) and the like.

3. The method of using a magnetic levitation rotor high precision dynamic balancing correction device of claim 1, wherein: The radial electromagnetic bearing (1_2), the rotor assembly radial displacement sensor (1_3), the magnetic suspension position closed-loop controller (2_4) and the associated sensor signal processing circuit and power amplification circuit jointly constitute a magnetic suspension radial position control system of the rotor assembly (1_1).

4. The method of using a magnetic levitation rotor high precision dynamic balancing correction device of claim 2, wherein: The three-phase motor stator (1_4), the rotor (1_1_3) and the motor PWM drive and controller (2_5) constitute an axial rotation control system of the magnetic suspension rotor assembly (1_1), and the axial electromagnetic bearing (1_5), the axial magnetic suspension bearing rotor (1_1_6), an axial position component in the magnetic suspension position closed-loop controller (2_4) and a rotor assembly axial displacement sensor control constitute an axial position control system of the rotor assembly (1_1).

5. The method of using a magnetic levitation rotor high precision dynamic balancing correction device of claim 2, wherein: The magnetic suspension rotor assembly (1_1) is designed with a ring belt at both ends for dynamic balance correction machining.

6. The method of using a magnetic levitation rotor high precision dynamic balancing correction device of claim 1, wherein: The radial position closed-loop control algorithm of the magnetic suspension motor controller (2) is a reverse dynamics control algorithm.

7. The method of using a magnetic levitation rotor high precision dynamic balancing correction device of claim 1, wherein: The inertia product elements of the rotor inertia matrix of the magnetic suspension motor dynamic mathematical model (3) are functions of the rotor assembly dynamic balance imbalance parameters, which are a 3-dimensional vector composed of the mass representing static imbalance, the mass representing dynamic imbalance, and the angle representing the mass distribution. The magnetic suspension motor dynamic mathematical model (3) includes functional modules simulating the dynamic characteristics of the magnetic suspension bearing current control loop and the rotor assembly radial position sensor.

8. The method of using a magnetic levitation rotor high precision dynamic balancing correction device of claim 1, wherein: The dynamic balance imbalance parameter computer optimization algorithm (5) is to extract the synchronous components with the same frequency as the rotation of the rotor assembly from the magnetic suspension bearing electromagnet currents in the actual physical system and the computer simulation system respectively, and to use the vector difference between the two to form the objective function of the computer optimization algorithm.

9. The method of using a magnetic levitation rotor high precision dynamic balancing correction device of claim 8, wherein: The synchronous components are obtained by rotating the magnetic suspension bearing electromagnet current vector from the stationary coordinate system to the rotor rotating coordinate system and then low-pass filtering.

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