Dynamic Characteristics of Flexible Rotor System of High Speed Motor with Magnetic Bearings

2020 ◽  
Author(s):  
Haijiang Kou ◽  
Li Zeng ◽  
Zhida Zhu ◽  
Min Dai ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Rotor System ◽  
Magnetic Bearings ◽  
Flexible Rotor

Estimation of Active Magnetic Bearings (AMB) Dynamic Parameters and Residual Mass Imbalance Using FEM With PID Controller and Identification Algorithm of a Flexible Rotor System Fully Levitated on AMB

2019 ◽  
Author(s):  
Bala Murugan S. ◽  
R. K. Behera
Keyword(s):  
Pid Controller ◽  
Rotor System ◽  
Magnetic Bearings ◽  
Identification Algorithm ◽  
Dynamic Parameters ◽  
Active Magnetic Bearings ◽  
Flexible Rotor ◽  
Residual Mass ◽  
Mass Imbalance ◽  
Least Squares Fit

Abstract The dynamic analyses of rotating systems are always a testing task to obtain the definite results. This paper carries the dynamic modelling, analysis and identification of coupled flexible rotor system supported by an auxiliary Active Magnetic Bearings (AMBs). An identification algorithm is used to estimate the dynamic parameters of AMB, and rotor residual mass imbalance. The proposed algorithm is a right method for the analysis of fully levitated rotor on AMBs. Finite element method is used to model the dynamic flexible rotor system with PID controller. A conventional dynamic condensation technique is implemented in the development of identification algorithm to overcome the difficulty in numerical simulation. The least-squares fit technique is deployed to estimate the dynamic parameters in frequency domain. Then the algorithm is extended to find the misalignment forces and moments at the coupling point. Numerical study is carried to check the correctness of the algorithm. The proposed algorithm is yet to be tested to experimental results from a fully levitated rotor test rig supported with AMBs.

Balancing of High Speed Flexible Overhung Rotor: A Case Study

1993 ◽  
Author(s):  
V. Kamala
Keyword(s):  
High Speed ◽  
Rotor System ◽  
High Mode ◽  
Mode Shapes ◽  
Operating Speed ◽  
Flexible Rotor ◽  
Single Plane

Abstract This paper presents a case study of balancing a high speed overhung flexible rotor system. The system had several speeds, below the operating speed, where the amplitude of vibration was high. Mode shapes were obtained by measuring amplitude of 1X component and its phase at various locations & balancing was carried out by adding weights in a single plane.

Adaptive Synchronization Control Design for High-Speed Magnetic Bearings

1995 ◽  
Author(s):  
Li-Farn Yang ◽  
Jeen-Gwo Tsao
Keyword(s):  
Disturbance Rejection ◽  
High Speed ◽  
Feedforward Control ◽  
Rotating Disk ◽  
Rotor System ◽  
Magnetic Bearings ◽  
Adaptive Synchronization ◽  
Synchronization Control ◽  
Plant Variation ◽  
Adaptive Feedforward

Abstract The performance of actively controlled magnetic bearings is greatly degraded if subjected to unpredictable disturbances or system dynamic variations. This paper present an adaptive synchronization control on a magnetically suspended rotor system for disturbance rejection and plant variation compensation. The rotor system consists of a rotating disk mounted on a shaft which is actively positioned in the radial directions via two magnetic bearings at both ends. Under the synchronizing control, four displacements of shaft along bearing axes are coordinated such that the disturbed displacement can promptly be recovered with those undisturbed in a complementary way. Such motion synchronization requires strict regulation and adaptation through four local controllers with an adaptive feedforward control scheme. The local controllers can be linked by the coupling law, in which an error along one bearing axis can affect overall control loop of four axes. Two control algorithms are developed under the biaxial and quadaxial synchronization conditions, and their adaptation laws are optimized in an attempt to minimize the adaptation errors. Simulations of disturbance rejection responses will also be presented.

Optimization Design and Experimental Study of a Two-disk Rotor System Based on Multi-Island Genetic Algorithm

2019 ◽  
Vol 36 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Jingjing Huang ◽  
Longxi Zheng ◽  
Chris K Mechefske ◽  
Bingbing Han
Keyword(s):  
Genetic Algorithm ◽  
Vibration Amplitude ◽  
High Speed ◽  
Optimization Design ◽  
Critical Speed ◽  
Optimization Method ◽  
Rotor System ◽  
Flexible Rotor ◽  
Optimum Position ◽  
Transient Experiments

Abstract Based on rotor dynamics theory, a two-disk flexible rotor system representing an aero-engine with freely supported structure was established with commercial software ANSYS. The physical model of the two-disk rotor system was then integrated to the multidisciplinary design optimization software ISIGHT and the maximum vibration amplitudes experienced by the two disks when crossing the first critical speed were optimized using a multi-island genetic algorithm (MIGA). The optimization objective was to minimize the vibration amplitudes of the two disks when crossing the first critical speed. The position of disk 1 was selected as the optimization variable. The optimum position of disk 1 was obtained at the specified constraint that the variation of the first critical speed could not exceed the range of ±10 %. In order to validate the performance of the optimization design, the proof-of-transient experiments were conducted based on a high-speed flexible two-disk rotor system. Experimental results indicated that the maximum vibration amplitude of disk 1 when crossing the first critical speed declined by 60.9 % and the maximum vibration amplitude of disk 2 fell by 63.48 % after optimization. The optimization method found the optimum rotor positions of the flexible rotor system which resulted in minimum vibration amplitudes.

Fault Tolerant Magnetic Bearings

1999 ◽  
Vol 121 (3) ◽  
pp. 504-508 ◽  
Author(s):  
E. H. Maslen ◽  
C. K. Sortore ◽  
G. T. Gillies ◽  
R. D. Williams ◽  
S. J. Fedigan ◽  
...  
Keyword(s):  
Fault Tolerance ◽  
High Speed ◽  
Fault Tolerant ◽  
High Capacity ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Flexible Rotor ◽  
Variable Reluctance ◽  
Modular Redundancy ◽  
Bearing System

A fault tolerant magnetic bearing system was developed and demonstrated on a large flexible-rotor test rig. The bearing system comprises a high speed, fault tolerant digital controller, three high capacity radial magnetic bearings, one thrust bearing, conventional variable reluctance position sensors, and an array of commercial switching amplifiers. Controller fault tolerance is achieved through a very high speed voting mechanism which implements triple modular redundancy with a powered spare CPU, thereby permitting failure of up to three CPU modules without system failure. Amplifier/cabling/coil fault tolerance is achieved by using a separate power amplifier for each bearing coil and permitting amplifier reconfiguration by the controller upon detection of faults. This allows hot replacement of failed amplifiers without any system degradation and without providing any excess amplifier kVA capacity over the nominal system requirement. Implemented on a large (2440 mm in length) flexible rotor, the system shows excellent rejection of faults including the failure of three CPUs as well as failure of two adjacent amplifiers (or cabling) controlling an entire stator quadrant.

The Dynamic Analysis of SFD-Sliding Bearing Flexible Rotor System Based on Optimization Design

2012 ◽  
Vol 159 ◽  
pp. 355-360
Author(s):  
Ji Yan Wang ◽  
Rong Chun Guo ◽  
Xu Fei Si
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Critical Speed ◽  
Structural Parameters ◽  
Rotor System ◽  
Flexible Rotor ◽  
Optimization Analysis ◽  
Sliding Bearing ◽  
Critical Speeds ◽  
Design Variables

The paper establishes the mechanical model of SFD-sliding bearing flexible rotor system, adopting Runge-Kutta method to solve nonlinear differential equation, thus acquiring the unbalanced response curve and then gaining the first two critical speeds of the system. Meanwhile, the paper analyzes the sensitivity of the system on the first two critical speeds towards structural parameters, offering design variables to optimization analysis. Based on sensitivity analysis, genetic algorithm is employed to give an optimization analysis on critical speed, which aims to remove critical speed from working speed as much as possible. The critical speed ameliorates after the optimization which supplies theoretical basis as well as theoretical analysis towards the dynamic stability of high-speed rotor system and provides reference for the design of such rotor system.

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