Modeling and analysis of a novel conical magnetic bearing for vernier-gimballing magnetically suspended flywheel

2013 ◽  
Vol 228 (13) ◽  
pp. 2416-2425 ◽  
Author(s):  
Jiancheng Fang ◽  
Chune Wang ◽  
Jiqiang Tang
Keyword(s):  
Permanent Magnet ◽  
Degrees Of Freedom ◽  
Magnetic Coupling ◽  
Magnetic Bearing ◽  
Modeling And Analysis ◽  
Control Moment ◽  
Novel Structure ◽  
Force Coupling ◽  
Conical Structure ◽  
The Mathematical Model

The vernier-gimballing magnetically suspended flywheel can generate control moment in radial directions by tilting the spinning rotor to rotate around the radial axes. In order to reduce the extra tilting torque caused by the uniform distribution of flux density and the magnetic coupling among different channels, a novel 3 degrees of freedom conical permanent-magnet-biased magnetic bearing is proposed in the paper. The axial and radial stators are both designed with the normal directions of the midst faces directing to the centroid of the rotor, so as to decrease the extra torque by shortening the length of torque arm. A novel structure of radial X and Y stator poles separated by nonmagnetic material is proposed, and the upper and lower conical stators are designed to be mirror structures with each other, so that the magnetic coupling can be reduced. The mathematical model of the proposed permanent-magnet-biased magnetic bearing is constructed by methods of equivalent magnetic circuit and finite element. Calculations and simulations are carried out on the suspension force, extra tilting torque, and force coupling. The results show that with the conical structure, the extra tilting torque can be decreased from 10.83 Nm to 0.11 Nm when the rotor tilts around X axis for 1°. The magnetic forces among X, Y, and Z directions are almost decoupled even when the rotor shifts in some direction. All the results prove that the novel permanent-magnet-biased magnetic bearing is suitable for application in vernier-gimballing magnetically suspended flywheel.

scholarly journals Nonlinear Behavior of a Magnetic Bearing System

1995 ◽  
Vol 117 (3) ◽  
pp. 582-588 ◽  
Author(s):  
L. N. Virgin ◽  
T. F. Walsh ◽  
J. D. Knight
Keyword(s):  
Degrees Of Freedom ◽  
Initial Conditions ◽  
Nonlinear Behavior ◽  
Analytical Techniques ◽  
Magnetic Bearing ◽  
Forced Response ◽  
The Mathematical Model ◽  
Two Degree Of Freedom ◽  
Sensitivity To Initial Conditions ◽  
Bearing System

This paper describes the results of a study into the dynamic behavior of a magnetic bearing system. The research focuses attention on the influence of nonlinearities on the forced response of a two-degree-of-freedom rotating mass suspended by magnetic bearings and subject to rotating unbalance and feedback control. Geometric coupling between the degrees of freedom leads to a pair of nonlinear ordinary differential equations, which are then solved using both numerical simulation and approximate analytical techniques. The system exhibits a variety of interesting and somewhat unexpected phenomena including various amplitude driven bifurcational events, sensitivity to initial conditions, and the complete loss of stability associated with the escape from the potential well in which the system can be thought to be oscillating. An approximate criterion to avoid this last possibility is developed based on concepts of limiting the response of the system. The present paper may be considered as an extension to an earlier study by the same authors, which described the practical context of the work, free vibration, control aspects, and derivation of the mathematical model.

scholarly journals Modeling and Analysis of Coupling Performance of Dynamic Stiffness Models for a Novel Combined Radial-Axial Hybrid Magnetic Bearing

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Bangcheng Han ◽  
Shiqiang Zheng
Keyword(s):  
Degrees Of Freedom ◽  
Eddy Currents ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Magnetic Bearing ◽  
Coupling Coefficients ◽  
Dynamic Displacement ◽  
Modeling And Analysis ◽  
Magnetic Circuits ◽  
Save Energy

The combined radial-axial magnetic bearing (CRAMB) with permanent magnet creating bias flux can reduce the size, cost, and mass and save energy of the magnetic bearing. The CRAMB have three-degree-of-freedom control ability, so its structure and magnetic circuits are more complicated compared to those of the axial magnetic bearing (AMB) or radial magnetic bearing (RMB). And the eddy currents have a fundamental impact on the dynamic performance of the CRAMB. The dynamic stiffness model and its cross coupling problems between different degrees of freedom affected for the CRAMB are proposed in this paper. The dynamic current stiffness and the dynamic displacement stiffness models of the CRAMB are deduced by using the method of equivalent magnetic circuit including eddy current effect, but the dynamic current stiffness of the RMB unit is approximately equal to its static current stiffness. The analytical results of an example show that the bandwidth of the dynamic current stiffness of the AMB unit and the dynamic displacement stiffness of the CRAMB is affected by the time-varying control currents or air gap, respectively. And the dynamic current stiffness and the dynamic displacement stiffness between the AMB unit and the RMB unit are decoupled due to few coupling coefficients.

scholarly journals Nonlinear Behavior of a Magnetic Bearing System

1994 ◽  
Author(s):  
Lawrence N. Virgin ◽  
Thomas F. Walsh ◽  
Josiah D. Knight
Keyword(s):  
Degrees Of Freedom ◽  
Initial Conditions ◽  
Nonlinear Behavior ◽  
Analytical Techniques ◽  
Magnetic Bearing ◽  
Forced Response ◽  
The Mathematical Model ◽  
Two Degree Of Freedom ◽  
Sensitivity To Initial Conditions ◽  
Bearing System

This paper describes the results of a study into the dynamic behavior of a magnetic bearing system. The research focuses attention on the influence of nonlinearities on the forced response of a two-degree-of-freedom rotating mass suspended by magnetic bearings and subject to rotating unbalance and feedback control. Geometric coupling between the degrees of freedom leads to a pair of nonlinear ordinary differential equations which are then solved using both numerical simulation and approximate analytical techniques. The system exhibits a variety of interesting and somewhat unexpected phenomena including various amplitude driven bifurcational events, sensitivity to initial conditions and the complete loss of stability associated with the escape from the potential well in which the system can be thought to be oscillating. An approximate criterion to avoid this last possibility is developed based on concepts of limiting the response of the system. The present paper may be considered as an extension to an earlier study by the same authors which described the practical context of the work, free vibration, control aspects and derivation of the mathematical model.

Bearingless Permanent Magnet Synchronous Motor using Independent Control

2015 ◽  
Vol 6 (2) ◽  
pp. 233
Author(s):  
Normaisharah Mamat ◽  
Kasrul Abdul Karim ◽  
Zulkiflie Ibrahim ◽  
Tole Sutikno ◽  
Siti Azura Ahmad Tarusan ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Speed ◽  
High Performance ◽  
High Efficiency ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Magnetic Bearing ◽  
Force Model ◽  
The Mathematical Model

Bearingless permanent magnet synchronous motor (BPMSM) combines the characteristic of the conventional permanent magent synchronous motor and magnetic bearing in one electric motor. BPMSM is a kind of high performance motor due to having both advantages of PMSM and magnetic bearing with simple structure, high efficiency, and reasonable cost. The research on BPMSM is to design and analyse BPMSM by using Maxwell 2-Dimensional of ANSYS Finite Element Method (FEM). Independent suspension force model and bearingless PMSM model are developed by using the method of suspension force. Then, the mathematical model of electromagnetic torque and radial suspension force has been developed by using Matlab/Simulink. The relation between force, current, distance and other parameter are determined. This research covered the principle of suspension force, the mathematical model, FEM analysis and digital control system of bearingless PMSM. This kind of motor is widely used in high speed application such as compressors, pumps and turbines.

scholarly journals Dynamic Modeling and Analysis of Demagnetizing Rotor of Permanent Magnet Synchronous Motor

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Bifeng Zhou ◽  
Guoning Tang ◽  
Yiping Luo
Keyword(s):  
Permanent Magnet ◽  
Dynamic Modeling ◽  
Theoretical Basis ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
The Self ◽  
Dynamics Model ◽  
Modeling And Analysis ◽  
Self Gravity ◽  
The Mathematical Model

This study performs a dynamic modeling and analysis of the axial uniform demagnetization rotor of a motor to investigate the demagnetization peculiar for permanent magnet synchronous motor (PMSM). First, the air-gap change in the motor is analyzed by constructing a dual coordinate system of stator and rotor, and the unbalanced magnetic pull (UMP) model under uniform demagnetization and eccentricity is constructed. Second, combined with the UMP and the self-gravity, a dynamic model of the rotor under a uniform demagnetization and eccentricity is established. Lastly, the accuracy of the mathematical model of UMP under uniform demagnetization and eccentricity is confirmed by the mutual corroboration of Maxwell simulation and MATLAB calculation; and based on the dynamics model, the dynamic characteristics of the rotor system under different degrees of uniform demagnetization are studied. This study provides a theoretical basis for the accurate demagnetization fault diagnosis and vibration control of PMSMs in the future.

scholarly journals A Novel Integral 5-DOFs Hybrid Magnetic Bearing with One Permanent Magnet Ring Used for Turboexpander

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Bangcheng Han ◽  
Xu Liu ◽  
Shiqiang Zheng
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Controller Design ◽  
Low Cost ◽  
Magnetic Bearing ◽  
The One ◽  
3D Finite Element Method ◽  
Radial Magnetic Bearing ◽  
Thrust Magnetic Bearing

We propose a novel combined five-degrees-of-freedom (5-DOFs) hybrid magnetic bearing (HMB) with only one permanent magnet ring (PMR) used for turboexpanders. It has two radial magnetic bearing (RMB) units; each has four poles and one thrust magnetic bearing (TMB) to control 5-DOFs. Based on one PMR, the bias flux of the two radial magnetic bearing units and the one thrust magnetic bearing unit is constructed. As a result, ultra-high-speed, lower power loss, small size, and low cost can be achieved. Furthermore, the equivalent magnetic circuit method and 3D finite element method (FEM) are used to model and analyze the combined 5-DOFs HMB. The force-current, force-position, torque-coil currents, the torque-angle position, and the stiffness models of the combined 5-DOFs HMB are given. Moreover, its coupling problems between the RMB units and the AMB unit are also proposed in this paper. An example is given to clarify the mathematical models and the coupling problems, and the linearized models are proposed for the follow-up controller design.

Suspension force analysis of six-pole radial-axial magnetic bearing for energy storage flywheel

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040066
Author(s):  
Jintao Ju ◽  
Jiaan Wang ◽  
Yanfei Wang ◽  
Zhikang Wu ◽  
Ying Qin
Keyword(s):  
Degrees Of Freedom ◽  
Magnetic Bearing ◽  
Low Power Consumption ◽  
Force Analysis ◽  
Element Analysis ◽  
Compact Structure ◽  
Three Phase ◽  
Phase Converter ◽  
Current Characteristics ◽  
The Mathematical Model

This paper proposes a six-pole radial-axial hybrid magnetic bearing (RAHMB) used in a flywheel system. The radial and axial bias fluxes are generated by one permanent magnet and the radial control coils are driven by a three-phase converter. So, it has the advantages of compact structure, low power consumption and simple driver. First, the work principle is introduced. Then, the mathematical model is built. The force-current characteristics with different eccentricities, the coupling between radial two degrees of freedom (DOF) and the coupling between radial and axial DOF are analyzed based on the analytical model. Finally, the analyses are validated by 3D finite element analysis in the Maxwell software. The results have shown that the coupling between radial and axial DOF is very small. However, the force-current curves of radial two DOFs turn out to be nonlinear and coupled with the increase of rotor eccentricity.

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